Sex differences in the expression of hepatic drug metabolizing enzymes

Non-alcoholic Fatty Liver Disease as a Canonical Example of Metabolic Inflammatory-Based Liver Disease Showing a Sex-Specific Prevalence: Relevance of Estrogen Signaling

There is extensive evidence supporting the interplay between metabolism and immune response, that have evolved in close relationship, sharing regulatory molecules and signaling systems, to support biological functions. Nowadays, the disruption of this interaction in the context of obesity and overnutrition underlies the increasing incidence of many inflammatory-based metabolic diseases, even in a sex-specific fashion. During evolution, the interplay between metabolism and reproduction has reached a degree of complexity particularly high in female mammals, likely to ensure reproduction only under favorable conditions. Several factors may account for differences in the incidence and progression of inflammatory-based metabolic diseases between females and males, thus contributing to age-related disease development and difference in life expectancy between the two sexes. Among these factors, estrogens, acting mainly through Estrogen Receptors (ERs), have been reported to regulate several metabolic pathways and inflammatory processes particularly in the liver, the metabolic organ showing the highest degree of sexual dimorphism. This review aims to investigate on the interaction between metabolism and inflammation in the liver, focusing on the relevance of estrogen signaling in counteracting the development and progression of non-alcoholic fatty liver disease (NAFLD), a canonical example of metabolic inflammatory-based liver disease showing a sex-specific prevalence. Understanding the role of estrogens/ERs in the regulation of hepatic metabolism and inflammation may provide the basis for the development of sex-specific therapeutic strategies for the management of such an inflammatory-based metabolic disease and its cardio-metabolic consequences.

Proteomic analysis revealed common, unique and systemic signatures in gender-dependent hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the most common liver cancer and is highly malignant. Male prevalence and frequent activation of the Ras signaling pathway are distinct characteristics of HCC. However, the underlying mechanisms remain to be elucidated. By exploring Hras12V transgenic mice showing male-biased hepatocarcinogenesis, we performed a high-throughput comparative proteomic analysis based on tandem-mass-tag (TMT) labeling combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) on the tissue samples obtained from HCC (T) and their paired adjacent precancerous (P) of Hras12V transgenic male and female mice (Ras-Tg) and normal liver (W) of wild-type male and female mice (Non-Tg). The further validation and investigation were performed using quantitative real-time PCR and western blot. Totally, 5193 proteins were quantified, originating from 5733 identified proteins. Finally, 1344 differentially expressed proteins (DEPs) (quantified in all examined samples; |ratios| ≥ 1.5, p < 0.05) were selected for further analysis. Comparison within W, P, and T of males and females indicated that the number of DEPs in males was much higher than that in females. Bioinformatics analyses showed the common and unique cluster-enriched items between sexes, indicating the common and gender-disparate pathways towards HCC. Expression change pattern analysis revealed HCC positive/negative-correlated and ras oncogene positive/negative-correlated DEPs and pathways. In addition, it showed that the ras oncogene gradually and significantly reduced the responses to sex hormones from hepatocytes to hepatoma cells and therefore shrunk the gender disparity between males and females, which may contribute to the cause of the loss of HCC clinical responses to the therapeutic approaches targeting sex hormone pathways. Additionally, gender disparity in the expression levels of key enzymes involved in retinol metabolism and terpenoid backbone/steroid biosynthesis pathways may contribute to male prevalence in hepatocarcinogenesis. Further, the biomarkers, SAA2, Orm2, and Serpina1e, may be sex differences. In conclusion, common and unique DEPs and pathways toward HCC initiated by ras oncogene from sexually dimorphic hepatocytes provide valuable and novel insights into clinical investigation and practice.

Sex-specific neurobiological actions of prophylactic (R,S)-ketamine, (2R,6R)-hydroxynorketamine, and (2S,6S)-hydroxynorketamine

Enhancing stress resilience in at-risk populations could significantly reduce the incidence of stress-related psychiatric disorders. We have previously reported that the administration of (R,S)-ketamine prevents stress-induced depressive-like behavior in male mice, perhaps by altering α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated transmission in hippocampal CA3. However, it is still unknown whether metabolites of (R,S)-ketamine can be prophylactic in both sexes. We administered (R,S)-ketamine or its metabolites (2R,6R)-hydroxynorketamine ((2R,6R)-HNK) and (2S,6S)-hydroxynorketamine ((2S,6S)-HNK) at various doses 1 week before one of a number of stressors in male and female 129S6/SvEv mice. Patch clamp electrophysiology was used to determine the effect of prophylactic drug administration on glutamatergic activity in CA3. To examine the interaction between ovarian hormones and stress resilience, female mice also underwent ovariectomy (OVX) surgery and a hormone replacement protocol prior to drug administration. (2S,6S)-HNK and (2R,6R)-HNK protected against distinct stress-induced behaviors in both sexes, with (2S,6S)-HNK attenuating learned fear in male mice, and (2R,6R)-HNK preventing stress-induced depressive-like behavior in both sexes. (R,S)-ketamine and (2R,6R)-HNK, but not (2S,6S)-HNK, attenuated large-amplitude AMPAR-mediated bursts in hippocampal CA3. All three compounds reduced N-methyl-D-aspartate receptor (NMDAR)-mediated currents 1 week after administration. Furthermore, ovarian-derived hormones were necessary for and sufficient to restore (R,S)-ketamine- and (2R,6R)-HNK-mediated prophylaxis in female mice. Our data provide further evidence that resilience-enhancing prophylactics may alter AMPAR-mediated glutamatergic transmission in CA3. Moreover, we show that prophylactics against stress-induced depressive-like behavior can be developed in a sex-specific manner and demonstrate that ovarian hormones are necessary for the prophylactic efficacy of (R,S)-ketamine and (2R,6R)-HNK in female mice.

Sex Differences in Rotenone Sensitivity Reflect the Male-to-Female Ratio in Human Parkinson's Disease Incidence

There is a critical need to include female subjects in disease research; however, in Parkinson's disease, where the male-to-female incidence is about 1.5-to-1, the majority of preclinical research is conducted in male animals. The mitochondrial complex I inhibitor, rotenone, is selectively toxic to dopaminergic neurons, and reproduces several neuropathological features of Parkinson's disease, including α-synuclein pathology. Rotenone has been primarily utilized in male Lewis rats; however, pilot studies in age-matched female Lewis rats revealed that our usual dose (2.8 mg/kg/day intraperitoneal [i.p.]) did not cause dopaminergic neurodegeneration. Therefore, we compared rotenone-treated males (2.8 mg/kg/day, i.p.) to females at increasing doses (2.8 mg/kg/day, 3.2 mg/kg/day, 3.6 mg/kg/day, and 1.6 mg/kg bis in die, i.p.). Female rats receiving 3.2 mg/kg, and 3.6 mg/kg rotenone displayed significant loss of dopaminergic neurons in the substantia nigra as assessed by stereology, which was accompanied by a loss of striatal dopaminergic terminals. Even at these higher doses, however, females showed less inflammation, and less accumulation of α-synuclein and transferrin, possibly as a result of preserved autophagy. Thus, the bias toward increased male incidence of human Parkinson's disease is reflected in the rotenone model. Whether such sex differences will translate into differences in responses to mechanism-driven therapeutic interventions remains to be determined.

Cystic Fibrosis and Genotype-Dependent Therapy: Is There a Need for a Sex-Specific Therapy?

Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulation (CFTR) anion channel. Loss of CFTR protein and/or function disrupts chloride, bicarbonate, and fluid transport and also impacts epithelial sodium transport. Such altered ion and fluid transport produces mucus obstruction, inflammation, pulmonary infection, and damage to multiple organs. Although an autosomal disease, it is apparent that gender differences in life expectancy and quality of life do exist. Conventionally established therapies have treated the downstream sequelae of CFTR dysfunction and have led to a steady increase in life expectancy. Physicians now have access to medications that treat the basic defect in CF, in the form of CFTR modulators. These drugs target the trafficking and/or function of CFTR to improve clinical outcomes for patients. This review summarizes the science behind CFTR modulators and shows how these drugs have dramatically changed how patients with CF are treated. Surprisingly, although the drug target(s) are identical in males and females, CF females seem to display a greater improvement than their male counterparts.

Comparative assessment for rat strain differences in metabolic profiles of 14 drugs in Wistar Han and Sprague Dawley hepatocytes

Knowledge of inter-strain and inter-gender differences in drug metabolism studies is important for animal selection in pharmacokinetic and toxicological studies. The effects of rat strain and gender in in vitro metabolism were investigated in Sprague Dawley (SD) and Wister Han (WH) rats based on the hepatocyte metabolic profiles of 14 small molecule drugs. Similarities were found between the hepatocyte metabolic clearances of SD and WH strains, suggesting that only one strain can be confidently used for the evaluation of hepatic clearance. Neither strain of rat was preferable over the other to cover human metabolites. Higher similarities in metabolic pathways were found between the same gender than the same strain. Differences in metabolite identities, metabolite formation rates and potential biotransformation pathways were observed between SD and WH rat strains. Eleven metabolites from six drugs were "disproportionally" formed between SD and WH rats. The use of a specific rat strain model and gender for ADME and toxicity testing should, therefore, be carefully considered as metabolic profiles may differ, even though metabolic clearance was similar between SD and WH rats.

Female-specific activation of pregnane X receptor mediates sex difference in fetal hepatotoxicity by prenatal monocrotaline exposure

Pyrrolizidine alkaloids (PAs) are a group of hepatic toxicant widely present in plants. Cytochrome P450 (CYP) 3A plays a key role in metabolic activation of PAs to generate electrophilic metabolites, which is the main cause of hepatotoxicity. We have previously demonstrated the sex difference in developmental toxicity and hepatotoxicity in fetal rats exposed to monocrotaline (MCT), a representative toxic PA. The aim of this study was to explore the underlying mechanism. 20 mg·kg^-1·d^-1 MCT was intragastrically given to pregnant Wistar rats from gestation day 9 to 20. CYP3As expression and pregnane X receptor (PXR) activation were specifically enhanced in female fetal liver. After MCT treatment, we also observed a significant increase of CYP3As expression in LO2 cells (high PXR level) or hPXR-transfected HepG2 cells (low PXR level). Employing hPXR and CYP3A4 dual-luciferase reporter gene assay, we confirmed the agonism effect of MCT on PXR-dependent transcriptional activity of CYP3A4. Agonism and antagonism of the androgen receptor (AR) either induced or blocked MCT-induced PXR activation, respectively. This study was the first report identifying that MCT served as PXR agonist to induce CYP3A expression. CYP3A induction may increase self-metabolic activation of MCT and subsequently lead to more severe hepatotoxicity in female fetus. While in male, during the intrauterine period, activated AR by testosterone secretion from developing testes represses MCT-induced PXR activation and CYP3A induction, which may partially protect male fetus from MCT-induced hepatotoxicity.

Impact of 3D genome organization, guided by cohesin and CTCF looping, on sex-biased chromatin interactions and gene expression in mouse liver

Several thousand sex-differential distal enhancers have been identified in mouse liver; however, their links to sex-biased genes and the impact of any sex-differences in nuclear organization and chromatin interactions are unknown. To address these issues, we first characterized 1847 mouse liver genomic regions showing significant sex differential occupancy by cohesin and CTCF, two key 3D nuclear organizing factors. These sex-differential binding sites were primarily distal to sex-biased genes but rarely generated sex-differential TAD (topologically associating domain) or intra-TAD loop anchors, and were sometimes found in TADs without sex-biased genes. A substantial subset of sex-biased cohesin-non-CTCF binding sites, but not sex-biased cohesin-and-CTCF binding sites, overlapped sex-biased enhancers. Cohesin depletion reduced the expression of male-biased genes with distal, but not proximal, sex-biased enhancers by >10-fold, implicating cohesin in long-range enhancer interactions regulating sex-biased genes. Using circularized chromosome conformation capture-based sequencing (4C-seq), we showed that sex differences in distal sex-biased enhancer-promoter interactions are common. Intra-TAD loops with sex-independent cohesin-and-CTCF anchors conferred sex specificity to chromatin interactions indirectly, by insulating sex-biased enhancer-promoter contacts and by bringing sex-biased genes into closer proximity to sex-biased enhancers. Furthermore, sex-differential chromatin interactions involving sex-biased gene promoters, enhancers, and lncRNAs were associated with sex-biased binding of cohesin and/or CTCF. These studies elucidate how 3D genome organization impacts sex-biased gene expression in a non-reproductive tissue through both direct and indirect effects of cohesin and CTCF looping on distal enhancer interactions with sex-differentially expressed genes.

Comparison of rat fetal sex determination using placental gDNA and mRNA via qRT-PCR

A growing need exists to consider fetal sex as a biological variable and accurately assess sex-specific effects. Among the multiple methods used to determine fetal sex, quantitative real-time polymerase chain reaction (qRT-PCR) of Sry (sex-determining region Y) with genomic DNA (gDNA) is commonly used in addition to use of methodologies such as transcriptomics and detection of Barr body. However, Sry messenger RNA (mRNA), a product of Sry gDNA, has not been previously assessed for sex determination. Using placental samples from timed-pregnant Wistar rats at gestational day (GD) 16, this study assessed the compatibility of Sry detection using gDNA versus mRNA to determine fetal sex. Samples used in this current study come from a larger study that investigated trichloroethylene (TCE) reproductive toxicity and potential modulation by N-acetyl-L-cysteine (NAC) and aminooxyacetic acid (AOAA). In 90 out of 91 samples, the sex classification determined by gDNA matched the sex classification determined by mRNA analyzing Sry (Sry/B2m) values. For both gDNA and mRNA, statistically significant differences in Sry/B2m values between males and females were observed with samples considered in totality and when samples were separated by treatment groups (all comparisons were p<0.01 or below, and all but two comparisons were p<0.001 or below). Finally, the validity of using Sry Cq values to determine fetal sex and the B2m reference gene were also discussed. Together, this study suggests that determination of fetal sex in Wistar rats can be accomplished using Sry measurements in gDNA or mRNA with highly compatible results.

Intramuscular antagonism of the G-protein coupled estrogen receptor 1 partially affects dimorphic characteristics of the syrinx, but is ineffective within the neural song circuit of zebra finches

Within the zebra finch song system, robust sex differences exist that enable singing behavior in males, but not females. Estradiol is a potent contributor to this process, but how and through which receptor(s) it acts is not clear. Historically, pharmacological manipulations of nuclear estrogen receptors have yielded conflicting results possibly due to method of drug delivery. More recently, the membrane bound G-protein coupled estrogen receptor 1 (GPER1) has also been identified as a potential candidate, but its function has not been fully described. To further investigate the role of GPER1, and the importance of the route of drug administration, a specific antagonist (G-15) was intramuscularly administered to zebra finches for 25 days, starting on the day of hatching. G-15 significantly decreased muscle fiber sizes of ventralis and dorsalis in the syrinx of males only. Dimorphic characteristics of the neural song system were unaffected by this manipulation in either sex. These results contrast with a study in which G-15 was intracranially delivered. In males, select song nuclei were decreased in volume, and in females, syrinx muscle fiber size was increased. Together, these results support the hypothesis that estrogens acting through GPER1 influence dimorphic development of the song system, and that method of drug administration is important in this species.

Organoid technology in female reproductive biomedicine

Recent developments in organoid technology are revolutionizing our knowledge about the biology, physiology, and function of various organs. Female reproductive biology and medicine also benefit from this technology. Organoids recapitulate features of different reproductive organs including the uterus, fallopian tubes, and ovaries, as well as trophoblasts. The genetic stability of organoids and long-lasting commitment to their tissue of origin during long-term culture makes them attractive substitutes for animal and in vitro models. Despite current limitations, organoids offer a promising platform to address fundamental questions regarding the reproductive system's physiology and pathology. They provide a human source to harness stem cells for regenerative medicine, heal damaged epithelia in specific diseases, and study biological processes in healthy and pathological conditions. The combination of male and female reproductive organoids with other technologies, such as microfluidics technology, would enable scientists to create a multi-organoid-on-a-chip platform for the next step to human-on-a-chip platforms for clinical applications, drug discovery, and toxicology studies. The present review discusses recent advances in producing organoid models of reproductive organs and highlights their applications, as well as technical challenges and future directions.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Hepatic Transcript Profiles of Cytochrome P450 Genes Predict Sex Differences in Drug Metabolism

Safety assessments of new drug candidates are an important part of the drug development and approval process. Often, possible sex-associated susceptibilities are not adequately addressed, and better assessment tools are needed. We hypothesized that hepatic transcript profiles of cytochrome P450 (P450) enzymes can be used to predict sex-associated differences in drug metabolism and possible adverse events. Comprehensive hepatic transcript profiles were generated for F344 rats of both sexes at nine ages, from 2 weeks (preweaning) to 104 weeks (elderly). Large differences in the transcript profiles of 29 drug metabolizing enzymes and transporters were found between adult males and females (8-52 weeks). Using the PharmaPendium data base, 41 drugs were found to be metabolized by one or two P450 enzymes encoded by sexually dimorphic mRNAs and thus were candidates for evaluation of possible sexually dimorphic metabolism and/or toxicities. Suspension cultures of primary hepatocytes from three male and three female adult rats (10-13 weeks old) were used to evaluate the metabolism of 11 drugs predicted to have sexually dimorphic metabolism. The pharmacokinetics of the drug or its metabolite was analyzed by liquid chromatography/tandem mass spectrometry using multiple reaction monitoring. Of those drugs with adequate metabolism, the predicted significant sex-different metabolism was found for six of seven drugs, with half-lives 37%-400% longer in female hepatocytes than in male hepatocytes. Thus, in this rat model, transcript profiles may allow identification of potential sex-related differences in drug metabolism. SIGNIFICANCE STATEMENT: The present study showed that sex-different expression of genes coding for drug metabolizing enzymes, specifically cytochrome P450s, could be used to predict sex-different drug metabolism and, thus, provide a new tool for protecting susceptible subpopulations from possible adverse drug events.

Effect of Genotype and Sex of the Host on the Bioavailability of Novel Albendazole Microcrystals Based on Chitosan and Cellulose Derivatives

Albendazole (ABZ), an anthelmintic compound widely used in the treatment of systemic nematode infections, is included in the list of class II drugs based on the Biopharmaceutical Classification System. ABZ has limited effectiveness due to its poor water solubility and consequent low bioavailability. Bioavailability of novel ABZ microcrystals based on hydroxyethylcellulose (S4A) or chitosan (S10A) was studied in male and female mice of two inbred lines, from the murine CBi-IGE model of trichinellosis, differing in susceptibility to this parasitosis (line CBi/L, resistant; line CBi+, susceptible). ABZ microcrystals were administered orally, and albendazole sulfoxide (ABZSO) was quantified in plasma by high-performance liquid chromatography. Mice given the microcrystals showed a significant increase in maximum plasmatic concentration (C_max) compared with those receiving pure ABZ (P < 0.01). In both genotypes, males and females given S4A had higher C_max than those receiving S10A (P < 0.05). CBi/L showed a greater C_max than CBi+ (significantly different only in females treated with S4A (P = 0.001)). CBi/L females attained a higher C_max than males (P < 0.05). No sex effect was observed for this variable in CBi+ (P > 0.05). The results of the pharmacokinetic analysis indicate that the microcrystalline formulations optimize ABZ bioavailability, both in males and females, S4A being the best system in CBi/L mice and S10A in CBi+. In summary, the microcrystals increased ABZ bioavailability, and under the conditions of this investigation, both host genotype and sex influenced the pharmacokinetic parameters measured.

Sex-biased genetic programs in liver metabolism and liver fibrosis are controlled by EZH1 and EZH2

Sex differences in the incidence and progression of many liver diseases, including liver fibrosis and hepatocellular carcinoma, are associated with sex-biased hepatic expression of hundreds of genes. This sexual dimorphism is largely determined by the sex-specific pattern of pituitary growth hormone secretion, which controls a transcriptional regulatory network operative in the context of sex-biased and growth hormone-regulated chromatin states. Histone H3K27-trimethylation yields a major sex-biased repressive chromatin mark deposited at many strongly female-biased genes in male mouse liver, but not at male-biased genes in female liver, and is catalyzed by polycomb repressive complex-2 through its homologous catalytic subunits, Ezh1 and Ezh2. Here, we used Ezh1-knockout mice with a hepatocyte-specific knockout of Ezh2 to investigate the sex bias of liver H3K27-trimethylation and its functional role in regulating sex-differences in the liver. Combined hepatic Ezh1/Ezh2 deficiency led to a significant loss of sex-biased gene expression, particularly in male liver, where many female-biased genes were increased in expression while male-biased genes showed decreased expression. The associated loss of H3K27me3 marks, and increases in the active enhancer marks H3K27ac and H3K4me1, were also more pronounced in male liver. Further, Ezh1/Ezh2 deficiency in male liver, and to a lesser extent in female liver, led to up regulation of many genes linked to liver fibrosis and liver cancer, which may contribute to the observed liver pathologies and the increased sensitivity of these mice to hepatotoxin exposure. Thus, Ezh1/Ezh2-catalyzed H3K27-trimethyation regulates sex-dependent genetic programs in liver metabolism and liver fibrosis through its sex-dependent effects on the epigenome, and may thereby determine the sex-bias in liver disease susceptibility.

Sex-differences in the expression of genes in liver have a direct impact on liver diseases whose incidence and severity is sex-biased, and is controlled by hormones that regulate chemical alterations to histone proteins used to package chromosomal DNA. However, a direct demonstration of the functional importance of such sex differences in histone protein modifications has been elusive. Here, we address this question using a mouse model deficient in two enzymes, Ezh1/Ezh2, which generate the histone repressive mark H3K27me3. Remarkably, although H3K27me3 marks are formed by Ezh1/Ezh2 throughout the genome, loss of liver Ezh1/Ezh2 preferentially disrupts the control of sex-biased genes, with expression increasing in male mouse liver for many female-biased genes and decreasing for many male-biased genes. Sex-biased H3K27me3 repressive marks were abolished, and there was a gain of active histone marks at gene enhancers. We also found increased expression of many genes associated with liver fibrosis and hepatocellular carcinoma, which may help explain the increased sensitivity of Ezh1/Ezh2-deficient livers to hepatotoxic chemicals whose exposure may lead to sex differences in liver disease incidence and susceptibility. Thus, our findings highlight the potential role of sex differences in histone modifications catalyzed by Ezh1/Ezh2 in widespread sex differences in liver diseases.

Early Transcriptional Changes within Liver, Adrenal Gland, and Lymphoid Tissues Significantly Contribute to Ebola Virus Pathogenesis in Cynomolgus Macaques

Ebola virus (EBOV) continues to pose a significant threat to human health, as evidenced by the 2013-2016 epidemic in West Africa and the ongoing outbreak in the Democratic Republic of the Congo. EBOV causes hemorrhagic fever, organ damage, and shock culminating in death, with case fatality rates as high as 90%. This high lethality combined with the paucity of licensed medical countermeasures makes EBOV a critical human pathogen. Although EBOV infection results in significant damage to the liver and the adrenal glands, little is known about the molecular signatures of injury in these organs. Moreover, while changes in peripheral blood cells are becoming increasingly understood, the host responses within organs and lymphoid tissues remain poorly characterized. To address this knowledge gap, we tracked longitudinal transcriptional changes in tissues collected from EBOV-Makona-infected cynomolgus macaques. Following infection, both liver and adrenal glands exhibited significant and early downregulation of genes involved in metabolism, coagulation, hormone synthesis, and angiogenesis; upregulated genes were associated with inflammation. Analysis of lymphoid tissues showed early upregulation of genes that play a role in innate immunity and inflammation and downregulation of genes associated with cell cycle and adaptive immunity. Moreover, transient activation of innate immune responses and downregulation of humoral immune responses in lymphoid tissues were confirmed with flow cytometry. Together, these data suggest that the liver, adrenal gland, and lymphatic organs are important sites of EBOV infection and that dysregulating the function of these vital organs contributes to the development of Ebola virus disease.IMPORTANCE Ebola virus (EBOV) remains a high-priority pathogen since it continues to cause outbreaks with high case fatality rates. Although it is well established that EBOV results in severe organ damage, our understanding of tissue injury in the liver, adrenal glands, and lymphoid tissues remains limited. We begin to address this knowledge gap by conducting longitudinal gene expression studies in these tissues, which were collected from EBOV-infected cynomolgus macaques. We report robust and early gene expression changes within these tissues, indicating they are primary sites of EBOV infection. Furthermore, genes involved in metabolism, coagulation, and adaptive immunity were downregulated, while inflammation-related genes were upregulated. These results indicate significant tissue damage consistent with the development of hemorrhagic fever and lymphopenia. Our study provides novel insight into EBOV-host interactions and elucidates how host responses within the liver, adrenal glands, and lymphoid tissues contribute to EBOV pathogenesis.

Methamphetamine administration increases hepatic CYP1A2 but not CYP3A activity in female guinea pigs

Methamphetamine use has increased over the past decade and the first use of methamphetamine is most often when women are of reproductive age. Methamphetamine accumulates in the liver; however, little is known about the effect of methamphetamine use on hepatic drug metabolism. Methamphetamine was administered on 3 occassions to female Dunkin Hartley guinea pigs of reproductive age, mimicking recreational drug use. Low doses of test drugs caffeine and midazolam were administered after the third dose of methamphetamine to assess the functional activity of cytochrome P450 1A2 and 3A, respectively. Real-time quantitative polymerase chain reaction was used to quantify the mRNA expression of factors involved in glucocorticoid signalling, inflammation, oxidative stress and drug transporters. This study showed that methamphetamine administration decreased hepatic CYP1A2 mRNA expression, but increased CYP1A2 enzyme activity. Methamphetamine had no effect on CYP3A enzyme activity. In addition, we found that methamphetamine may also result in changes in glucocorticoid bioavailability, as we found a decrease in 11β-hydroxysteroid dehydrogenase 1 mRNA expression, which converts inactive cortisone into active cortisol. This study has shown that methamphetamine administration has the potential to alter drug metabolism via the CYP1A2 metabolic pathway in female guinea pigs. This may have clinical implications for drug dosing in female methamphetamine users of reproductive age.

Sex steroid hormones differentially regulate CYP2D in female wild-type and CYP2D6-humanized mice

The CYP2D subfamily catalyses the metabolism of about 25% of prescribed drugs, including the majority of antidepressants and antipsychotics. At present, the mechanism of hepatic CYP2D regulation remains largely unknown. This study investigated the role of sex steroid hormones in CYP2D regulation. For this purpose, Cyp2d22 expression was assessed in the distinct phases of the estrous cycle of normocyclic C57BL/6J (WT) female mice. Cyp2d22 was also evaluated in ovariectomised WT and CYP2D6-humanized (hCYP2D6) mice that received hormonal supplementation with either 17β-estradiol (E2) and/or progesterone. Comparisons were also made to male mice. The data revealed that hepatic Cyp2d22 mRNA, protein and activity levels were higher at estrous compared to the other phases of the estrous cycle and that ovariectomy repressed Cyp2d22 expression in WT mice. Tamoxifen, an anti-estrogenic compound, also repressed hepatic Cyp2d22 via activation of GH/STAT5b and PI3k/AKT signaling pathways. Both hormones prevented the ovariectomy-mediated Cyp2d22 repression. In case of progesterone, this may be mediated by inhibition of the PI3k/AKT/FOX01 pathway. Notably, Cyp2d22 mRNA levels in WT males were similar to those in ovariectomised mice and were markedly lower compared to females at estrous, a differentiation potentially regulated by the GH/STAT5b pathway. Sex steroid hormone-related alterations in Cyp2d22 mRNA expression were highly correlated with Hnf1a mRNA. Interestingly, fluctuations in Cyp2d22 in hippocampus and cerebellum followed those in liver. In contrast to WT mice, ovariectomy induced hepatic CYP2D6 expression in hCYP2D6 mice, whereas E2 and/or progesterone prevented this induction. Apparently, sex steroid hormones display a significant gender- and species-specific role in the regulation of CYP2D.

Feeding brown fat: dietary phytochemicals targeting non-shivering thermogenesis to control body weight

Excessive adipose accumulation, which is the main driver for the development of secondary metabolic complications, has reached epidemic proportions and combined pharmaceutical, educational and nutritional approaches are required to reverse the current rise in global obesity prevalence rates. Brown adipose tissue (BAT) is a unique organ able to dissipate energy and thus a promising target to enhance BMR to counteract a positive energy balance. In addition, active BAT might support body weight maintenance after weight loss to prevent/reduce relapse. Natural products deliver valuable bioactive compounds that have historically helped to alleviate disease symptoms. Interest in recent years has focused on identifying nutritional constituents that are able to induce BAT activity and thereby enhance energy expenditure. This review provides a summary of selected dietary phytochemicals, including isoflavones, catechins, stilbenes, the flavonoids quercetin, luteolin and resveratrol as well as the alkaloids berberine and capsaicin. Most of the discussed phytochemicals act through distinct molecular pathways e.g. sympathetic nerve activation, AMP-kinase signalling, SIRT1 activity or stimulation of oestrogen receptors. Thus, it might be possible to utilise this multitude of pathways to co-activate BAT using a fine-tuned combination of foods or combined nutritional supplements.

Sex and gender differences in Alzheimer's disease: current challenges and implications for clinical practice: Position paper of the Dementia and Cognitive Disorders Panel of the European Academy of Neurology

Alzheimer's disease (AD) is characterized by high heterogeneity in disease manifestation, progression and risk factors. High phenotypic variability is currently regarded as one of the largest hurdles in early diagnosis and in the design of clinical trials; there is therefore great interest in identifying factors driving variability that can be used for patient stratification. In addition to genetic and lifestyle factors, the individual's sex and gender are emerging as crucial drivers of phenotypic variability. Evidence exists on sex and gender differences in the rate of cognitive deterioration and brain atrophy, and in the effect of risk factors as well as in the patterns of diagnostic biomarkers. Such evidence might be of high relevance and requires attention in clinical practice and clinical trials. However, sex and gender differences are currently seldom appreciated; importantly, consideration of sex and gender differences is not currently a focus in the design and analysis of clinical trials for AD. The objective of this position paper is (i) to provide an overview of known sex and gender differences that might have implications for clinical practice, (ii) to identify the most important knowledge gaps in the field (with a special regard to clinical trials) and (iii) to provide conclusions for future studies. This scientific statement is endorsed by the European Academy of Neurology.

Impact of host and environmental factors on β-glucuronidase enzymatic activity: implications for gastrointestinal serotonin

The gastrointestinal tract houses a reservoir of bacterial-derived enzymes that can directly catalyze the metabolism of drugs, dietary elements and endogenous molecules. Both host and environmental factors may influence this enzymatic activity, with the potential to dictate the availability of the biologically-active form of endogenous molecules in the gut and influence inter-individual variation in drug metabolism. We aimed to investigate the influence of the microbiota, and the modulation of its composition, on fecal enzymatic activity. Intrinsic factors related to the host, including age, sex and genetic background, were also explored. Fecalase, a cell-free extract of feces, was prepared and used in a colorimetric-based assay to quantify enzymatic activity. To demonstrate the functional effects of fecal enzymatic activity, we examined β-glucuronidase-mediated cleavage of serotonin β-d-glucuronide (5-HT-GLU) and the resultant production of free 5-HT by HPLC. As expected, β-glucuronidase and β-glucosidase activity were absent in germ-free mice. Enzymatic activity was significantly influenced by mouse strain and animal species. Sex and age significantly altered metabolic activity with implications for free 5-HT. β-Glucuronidase and β-glucosidase activity remained at reduced levels for nearly two weeks after cessation of antibiotic administration. This effect on fecalase corresponded to significantly lower 5-HT levels as compared with incubation with pre-antibiotic fecalase from the same mice. Dietary targeting of the microbiota using prebiotics did not alter β-glucuronidase or β-glucosidase activity. Our data demonstrate that multiple factors influence the activity of bacterial-derived enzymes which may have potential clinical implications for drug metabolism and the deconjugation of host-produced glucuronides in the gut.NEW & NOTEWORTHY This article explores a comprehensive range of host and environmental factors that introduce variability in the expression of bacterial-derived metabolic enzymes. Our results demonstrate that altered β-glucuronidase activity has implications for the bioavailability of luminal serotonin. The experimental approach employed, fecalase, provides a mechanistic basis and translational platform to further delineate the functional outputs of altered metabolic activity, and the associated physiological effects of microbiota-targeted interventions on host response to drugs and host-produced glucuronides.

Placenta as a target of trichloroethylene toxicity

Trichloroethylene (TCE) is an industrial solvent and a common environmental contaminant detected in thousands of hazardous waste sites. Risk of exposure is a concern for workers in occupations that use TCE as well as for residents who live near industries that use TCE or who live near TCE-contaminated sites. Although renal, hepatic and carcinogenic effects of TCE have been documented, less is known about TCE impacts on reproductive functions despite epidemiology reports associating maternal TCE exposure with adverse pregnancy outcomes. Toxicological evidence suggests that the placenta mediates at least some of the adverse pregnancy outcomes associated with TCE exposure. Toxicology studies show that the TCE metabolite, S-(1,2-dichlorovinyl)-l-cysteine (DCVC) generates toxic effects such as mitochondrial dysfunction, apoptosis, oxidative stress, and release of prostaglandins and pro-inflammatory cytokines in placental cell lines. Each of these mechanisms of toxicity have significant implications for placental functions and, thus, ultimately the health of mother and developing child. Despite these findings there remain significant gaps in our knowledge about effects of TCE on the placenta, including effects on specific placental cell types and functions as well as sex differences in response to TCE exposure. Due to the critical role that the placenta plays in pregnancy, future research addressing some of these knowledge gaps could lead to significant gains in public health.

Liver cancer incidence and mortality: Disparities based on age, ethnicity, health and nutrition, molecular factors, and geography

Liver cancer (LCa) is the fifth and eighth leading cause of cancer death for men and women, respectively. However, despite improvements in treatment strategies and options, it has limited therapeutic options. Worldwide, the prevalence of LCa varies widely. Various factors are associated with the development of LCa, and its incidence, morbidity, and mortality rates differ due to disparities that are multifactorial and complex, including genetic and geographic factors. The frequency of LCa varies by race/ethnicity, age and sex and relates to viral infections, lifestyle, nutrition, obesity, and health. In addition, various molecular factors, including cytokines, hormones, apoptosis, and mutations, are involved in disparities in the progression and mortality of LCa. Here, we provide an overall perspective on LCa by presenting available information on these associated factors and discussing their importance in its disproportionate incidences and clinical outcomes.

Sexual Dimorphism in Drug Metabolism and Pharmacokinetics

Background:

Sex and gender-based differences are observed well beyond the sex organs and affect several physiological and biochemical processes involved in the metabolism of drug molecules. It is essential to understand not only the sex and gender-based differences in the metabolism of the drug but also the molecular mechanisms involved in the regulation of drug metabolism for avoiding sex-related adverse effects of drugs in the human.

Method:

The articles on the sex and gender-based differences in the metabolism of drug molecules were retrieved from the Pub Med database. The articles were classified into the metabolism of the drug molecule, gene expression regulation of drug-metabolizing enzymes, the effect of sex hormones on the metabolism of drug, expression of drugmetabolizing enzymes, etc.

Result:

Several drug molecules are known, which are metabolized differently in males and females. These differences in metabolism may be due to the genomic and non-genomic action of sex hormones. Several other drug molecules still require further evaluation at the molecular level regarding the sex and gender-based differences in their metabolism. Attention is also required at the effect of signaling cascades associated with the metabolism of drug molecules.

Conclusion:

Sex and gender-based differences in the metabolism of drugs exist at various levels and it may be due to the genomic and non-genomic action of sex hormones. Detailed understanding of the effect of sex and related condition on the metabolism of drug molecules will help clinicians to determine the effective therapeutic doses of drugs dependingon the condition of patient and disease.

Understanding Idiosyncratic Toxicity: Lessons Learned from Drug-Induced Liver Injury

Idiosyncratic adverse drug reactions (IADRs) encompass a diverse group of toxicities that can vary by drug and patient. The complex and unpredictable nature of IADRs combined with the fact that they are rare makes them particularly difficult to predict, diagnose, and treat. Common clinical characteristics, the identification of human leukocyte antigen risk alleles, and drug-induced proliferation of lymphocytes isolated from patients support a role for the adaptive immune system in the pathogenesis of IADRs. Significant evidence also suggests a requirement for direct, drug-induced stress, neoantigen formation, and stimulation of an innate response, which can be influenced by properties intrinsic to both the drug and the patient. This Perspective will provide an overview of the clinical profile, mechanisms, and risk factors underlying IADRs as well as new approaches to study these reactions, focusing on idiosyncratic drug-induced liver injury.

Role of Sirt3 in Differential Sex-Related Responses to a High-Fat Diet in Mice

Metabolic homeostasis is differently regulated in males and females. Little is known about the mitochondrial Sirtuin 3 (Sirt3) protein in the context of sex-related differences in the development of metabolic dysregulation. To test our hypothesis that the role of Sirt3 in response to a high-fat diet (HFD) is sex-related, we measured metabolic, antioxidative, and mitochondrial parameters in the liver of Sirt3 wild-type (WT) and knockout (KO) mice of both sexes fed with a standard or HFD for ten weeks. We found that the combined effect of Sirt3 and an HFD was evident in more parameters in males (lipid content, glucose uptake, pparγ, cyp2e1, cyp4a14, Nrf2, MnSOD activity) than in females (protein damage and mitochondrial respiration), pointing towards a higher reliance of males on the effect of Sirt3 against HFD-induced metabolic dysregulation. The male-specific effects of an HFD also include reduced Sirt3 expression in WT and alleviated lipid accumulation and reduced glucose uptake in KO mice. In females, with a generally higher expression of genes involved in lipid homeostasis, either the HFD or Sirt3 depletion compromised mitochondrial respiration and increased protein oxidative damage. This work presents new insights into sex-related differences in the various physiological parameters with respect to nutritive excess and Sirt3.

In vitro drug metabolism and pharmacokinetics of a novel thiazolidinedione derivative, a potential anticancer compound

Thiazolidinediones are known for their activity against Type 2 diabetes and are currently being repurposed for their potent anti-cancer activity. In the present study, we have assessed in vitro metabolic properties and in vivo pharmacokinetic parameters of a novel thiazolidinedione derivative, BIT-15-67, a potential anticancer compound. BIT-15-67 showed low solubility in aqueous buffers at different pH values. The permeability was determined across the Caco-2 monolayer and BIT-15-67 showed high permeability and an efflux ratio of less than 2 suggesting that it is not a substrate of the efflux transporters (P-gp & BCRP). The plasma protein binding was evaluated by equilibrium dialysis and the compound exhibited moderate binding to mouse and rat plasma proteins. BIT-15-67 was stable (half-life > 30 min.) in mouse, rat, dog and human liver microsomes and unstable (half-life <15 min.) in rat hepatocytes suggesting possible Phase II metabolism. Liquid chromatography-tandem mass spectrometry was used to identify Phase I and Phase II metabolites. One of each Phase I and Phase II metabolites have been identified in rat hepatocytes samples. The BIT-15-67 is not an inhibitor of CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4. The PK parameters were determined in both male and female Wistar rats after single intravenous dose administration of BIT-15-67. In rats, the mean plasma clearance of BIT-15-67 was higher in males than in females and the terminal plasma elimination half-life was shorter in males than in females. The compound was highly distributed in the tissues. Overall, the absolute oral bioavailability was 5-fold higher in females (38 %) than in males (7 %). In female nude mice with tumors, BIT-15-67 was well distributed among the collected tissues with the highest concentration in the liver. The ratio of the concentrations in tumor vs. the plasma was 0.5 which could be an important attribute in the development of the compound for anti-cancer research.

Plasma pharmacokinetic and metabolism of [18F]THK-5317 are dependent on sex

INTRODUCTION

Tau deposition is one of the hallmarks of Alzheimer's disease (AD) and can be visualized and quantified using [¹⁸F]THK-5317 together with kinetic modeling. To determine the feasibility of this approach, we measured blood/plasma pharmacokinetics and radiotracer metabolism in female and male rats.

METHODS

Female and male rats (n = 11-12) were cannulated via the femoral artery for continuous blood sampling. Blood sampling was performed at regular intervals after intravenous injection of [¹⁸F]THK-5317. After collection of the last blood sample, animals were sacrificed, and organs were excised. Blood from minute 5, 20 and 60 was centrifuged to obtain plasma. Radiolabeled metabolites in plasma, brain, liver and urine were analyzed by radio-thin-layer chromatography (radio-TLC).

RESULTS

Plasma pharmacokinetics and metabolism were significantly different between female and male rats. [¹⁸F]THK-5317 plasma clearance was faster in female (0.66 ± 0.08 mL/h/kg BW) than in male (0.52 ± 0.11 mL/h/kg BW) rats (p = .005). The percentage of unmetabolized parent was significantly different between both sexes at 20 min and 60 min p.i. In the liver, a 1.6-fold higher radioactivity concentration was found in male versus female animals and in addition also the percentage of unmetabolized parent was different.

CONCLUSION

Our results show pronounced sex differences in blood/plasma pharmacokinetics and metabolism of [¹⁸F]THK-5317 in rats. Female animals showed a faster plasma clearance compared to males. These results underline the importance of investigating both sexes and also support the notion that individual input functions or sex-specific population-based input functions are needed for kinetic modeling analyses.

ADVANCES IN KNOWLEDGE

First preclinical study in rats showing pronounced sex differences in blood/plasma pharmacokinetics and metabolism of [¹⁸F]THK-5317.

IMPLICATIONS FOR PATIENT CARE

Sex-specific differences might also be present in humans and thus clinical trials should have adequate sample size to account for effects in men and women separately.

Genetic Background and Sex: Impact on Generalizability of Research Findings in Pharmacology Studies

Animal models consisting of inbred laboratory rodent strains have been a powerful tool for decades, helping to unravel the underpinnings of biological problems and employed to evaluate potential therapeutic treatments in drug discovery. While inbred strains demonstrate relatively reliable and predictable responses, using a single inbred strain alone or as a background to a mutation is analogous to running a clinical trial in a single individual and their identical twins. Indeed, complex etiologies drive the most common human diseases, and a single inbred strain that is a surrogate of a single genome, or data generated from a single sex, is not representative of the genetically diverse patient populations. Further, pharmacological and toxicology data generated in otherwise healthy animals may not translate to disease states where physiology, metabolism, and general health are compromised. The purpose of this chapter is to provide guidance for improving generalizability of preclinical studies by providing insight into necessary considerations for introducing systematic variation within the study design, such as genetic diversity, the use of both sexes, and selection of appropriate age and disease model. The outcome of implementing these considerations should be that reproducibility and generalizability of significant results are significantly enhanced leading to improved clinical translation.

Gender medicine: Towards a gender-specific treatment of neuropsychiatric disorders

Sex and gender are increasingly recognized as major influencing factors in disorders across all medical specialties. Even though there is ample evidence of sex and gender differences in neuropsychiatric disorders, a sex and gender-differentiated approach has not yet been sufficiently applied to diagnostics and management. Therefore, there is an urgent need to establish general recommendations and guidelines toward precision and sex/gender medicine, with regard to dosage, tolerability, interactions and side effects, sensitivity of diagnostic tests, and distinct treatment strategies. This chapter illustrates the current knowledge about sex and gender aspects in neuropsychiatric disorders, providing a base not only to assist the clinician in the handling of specific pathologic entities, but also to sensitize medical practitioners to consider sex and gender in clinical decision-making. As such, the chapter is a call to action to physicians and researchers to produce more sex- and gender-stratified evidence, leading to an acceleration of guideline development. Such novel guidelines will provide a base for medical education, of both medical students and specialists, as well as a reference point for practitioners, toward precision medicine.

Early Parenteral Administration of Ceftiofur has Gender-Specific Short- and Long-Term Effects on the Fecal Microbiota and Growth in Pigs from the Suckling to Growing Phase

Simple Summary

Antibiotics are commonly used in prevention and therapy of bacterial diseases in pig production. Although the main target of antibiotics are the pathogenic bacteria, they often disrupt the commensal gut microbiota as a whole, leading to intestinal disturbances. These detrimental effects have been well established for oral administration of antibiotics, whereas knowledge about potential disturbing effects of single parenteral antibiotic treatments on the gut microbiota development is limited. In this research, the impact of a single antibiotic injection on the first day of life on the maturation of the fecal microbiome and host growth performance was evaluated from the suckling to the growing phase. Results showed that a single antibiotic injection early in life influenced the bacterial community development in the short- and long-term and that this disturbance in the bacterial community was sex-specific. Present results further demonstrated that changes in the bacterial ecosystem of the gut may impair the growth performance of the growing pig. Thus, the results of the present study emphasize the importance of a proper and strict use of antibiotics in swine herds.

Abstract

Using ceftiofur during the first days of life is a common preventative strategy against several bacterial diseases in pig production. This study aimed to evaluate short- and long-term effects of early use of ceftiofur on the fecal microbiota development in suckling and growing pigs. Sixty-four piglets from eight litters were assigned to the antibiotic (AB; n = 32) or control group (control; n = 32). Twelve hours postpartum (day 0) AB piglets received an intramuscular injection of ceftiofur (5.0 mg/kg body weight) or a placebo. DNA was extracted from fecal samples collected on days 0, 12, 28, and 97 for deep-sequencing of the 16S rRNA gene. The AB administration disturbed the maturational changes in the fecal microbiome, whereby effects were sex-specific. Sex-related differences in AB metabolism in females and males may have caused these diverging AB-effects on the fecal microbiota. Especially the loss of bacterial diversity and of certain taxa in female AB pigs may have contributed to the decreased body weight of these females on day 97 of life. Taken together, this study showed that an AB injection with ceftiofur 12 h postpartum markedly affected the successional changes in the fecal microbiota composition in male and female pigs, with long-term consequences for host performance.

Effect of Gender on the Pharmacokinetics of ON 123300, A Dual Inhibitor of ARK5 and CDK4/6 for the Treatment of Cancer, in Rats

BACKGROUND AND OBJECTIVES

ON 123300, a small molecule dual inhibitor of the c-MYC activated kinases ARK5 and CDK4/6, is being developed as a novel drug candidate for the treatment of cancer. The objective of this research was to evaluate gender differences in the in vitro metabolism and in vivo systemic exposure of ON 123300 in rats.

METHODS

In vitro metabolism experiments (n = 2/group) were performed in rat liver microsomes from male and female donors. ON 123300 bislactate (final concentration 10 µM) was incubated with 0.5 mg/mL microsomes, and samples (100 µL) were withdrawn at specified incubation times over a period of 60 min, and immediately quenched and centrifuged. The supernatant was analyzed for ON 123300 and its metabolites by HPLC. ON 123300 (bislactate salt) pharmacokinetics were evaluated following intravenous (i.v.) (30 s infusion, 5 and 10 mg/kg) or oral administration (25 and 100 mg/kg) to male and female Sprague-Dawley rats (250-300 g). Following dosing, blood samples were collected over a time period up to 24 h. ON 123300 plasma concentrations were measured by LC-MS/MS. Pharmacokinetic parameters were estimated by non-compartmental analysis. Plasma and microsomal binding of ON 123300 and blood:plasma ratio were also determined.

RESULTS

ON 123300 displayed more rapid microsomal degradation in vitro in males compared to females, as reflected in intrinsic clearance (181 vs 53.1 µL/min/mg). This translated into a significantly higher exposure of ON 123300 following oral administration to female rats, with the area under the curve (AUC) increasing nearly 3-fold (5617 ± 1914 ng·h/mL) compared to males (AUC = 1965 ± 749 ng·h/mL). This gender effect was less pronounced following i.v. dosing, where the AUC was ~ 2-fold higher in females. Based on these results, the higher plasma exposure observed in females can be primarily attributed to reductions in both hepatic clearance and presystemic metabolism compared to males.

CONCLUSIONS

This investigation demonstrated a significantly lower metabolism of ON 123300 in female rats, which resulted in high systemic exposure. Additional testing is warranted to assess the potential clinical implications of these findings.

Urinary metabolites of organophosphate esters and implications for exposure pathways in adolescents from Eastern China

Ten urinary biomarkers of organophosphate esters (OPEs) from six parent OPEs were analyzed in urine from adolescents students in Eastern China. Bis (1,3-dichloro-2-propyl) phosphate, urinary biomarker of tris (1,3-dichloro-2-propyl) phosphate (TDCIPP), was detected in all urine samples with the highest residual concentration of 6.2 ng/mL (median). Bis (1-chloro-propyl) hydroxyl-2-propyl phosphate, dibutyl phosphate, biomarkers of tris (1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), respectively, and tris (2-chloroethyl) phosphate (TCEP), were also frequently detected with median concentrations of 1.5, 2.6 and 0.3 ng/mL, respectively. Results indicate that exposure to OPEs, in particular to TDCIPP, TNBP, TCIPP and TCEP, was highly prevalent for adolescent students. The exposure pathways of OPEs were then evaluated according to the OPE internal body burdens (IBBs). Three pathways were identified as the main pathways for adolescents exposed to OPEs including dermal absorption, oral intake of food and dust and inhalation.

Activated FXR promotes xenobiotic metabolism of T-2 toxin and attenuates oxidative stress in broiler chicken liver

The transmission of T-2 toxin and its metabolites into the edible tissues of poultry has potential effects on human health. The bile acid and xenobiotic system composes an intricate physiological network of chemoprotective and transporter-related functions, which ensures the detoxification and removal of harmful xenobiotic and endobiotic compounds from the body. This study revealed that cholic acid (CA), as one of the bile acids, promoted the metabolism of T-2 toxin in vivo by inducing the xenobiotic metabolism enzymes expression, thereby increasing the stress resistance and attenuating the oxidative stress. This study also indicated that dietary supplementation of 1% CA alleviated the mortality caused by T-2 toxin. Liver histology results demonstrated that CA supplementation significantly reduced inflammatory cell infiltration, sinusoidal expansion and congestion. Biochemistry results showed that the elevations of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and the increase in concentration of hydrogen peroxide (H₂O₂) in liver induced by the T-2 toxin were decreased by dietary supplementation of 1% CA. Additionally, CA supplementation led to the increase in superoxide dismutase (SOD) activity, but the decrease in catalase (CAT) activity in broiler chicken livers. Based on these findings, we propose that activation of FXR promotes T-2 toxin xenobiotic metabolism, and FXR plays a hepatoprotection role in liver injury induced by T-2 toxin.

Toxicokinetics of cis- and trans-Permethrin: Influence of Isomer, Maturation, and Sex

Permethrin exposure of children and adults is widespread in many populations, but knowledge of its relative toxicokinetics (TK) and health risks in immature age groups is lacking. Studies were conducted in rats to determine the influence of immaturity and sex (on plasma and target organ dosimetry of each of the insecticide’s 2 isomers, cis- and trans-permethrin [CIS and TRANS]). Postnatal day 15, 21, and 90 (adult), Sprague Dawley rats were orally administered a graduated series of doses of CIS and TRANS in corn oil. Serial sacrifices were conducted over 24 h to obtain plasma, brain, liver, skeletal muscle, and fat profiles of CIS and TRANS. Levels of TRANS decreased relatively rapidly, despite administration of relatively high doses. Concentrations of each isomer in plasma, brain, and other tissues monitored were inversely proportional to the animals’ age. The youngest pups exhibited 4-fold higher plasma and brain area under the curves than did adults. Little difference was observed in the TK of CIS or TRANS between adult male and female rats, other than higher initial plasma and liver CIS levels in females. Elevated exposure of the immature brain appears to be instrumental in increased susceptibility to the acute neurotoxicity of high-dose permethrin (Cantalamessa [1993]), but it remains to be established whether age-dependent TK is relevant to long-term, low-level risks.

Hepatic PGC-1α is not essential for fasting-induced cytochrome p450 regulation in mouse liver

Fasting has been shown to regulate the expression of the cytochrome p450 (CYP) enzyme system in the liver. However, the exact mechanism behind the fasting-induced regulation of the CYP's remains unknown. In the present study we tested the hypothesis that the peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), which is a key-regulator of energy metabolism, is responsible for the fasting-induced regulation of the CYP's. Lox/lox and liver specific PGC-1α (LKO) mice of both sexes, fasted for 18 h and the content of the CYP's as well as the hepatic metabolome was assessed. Fasting increased the mRNA content of Cyp2a4, Cyp2e1, Cyp3a11 and Cyp4a10. The fasting-induced response in Cyp4a10 mRNA content was different between lox/lox and LKO mice, while the absence of PGC-1α had no effect on the fasting-induced response for the other Cyp's. Moreover, the fasting-induced response in mRNA content of Sirtinus 1 and Perilipin 2 was different between lox/lox and LKO mice. Only the CYP1A isoform showed a fasting-induced response at the protein level. Absence of hepatic PGC-1α had no effect on the apparent metabolome, where fasting vs fed was the only discriminate in the following multivariate analysis. In conclusion, hepatic PGC-1α is not essential for the fasting-induced regulation of hepatic CYP's.

Stimulation of 5-HT2C serotonin receptor subtype in the hypothalamic arcuate nuclei (ARC) increases the cytochrome P450 activity in the liver

BACKGROUND

Our previous study has demonstrated that activation of the 5-HT2, but not 5-HT1 serotonin receptor type in the hypothalamic arcuate nucleus (ARC) is responsible for the neuroendocrine regulation of liver cytochrome P450. The goal of these studies was to determine whether 5-HT2C serotonin receptor subtype in the ARC is engaged in the regulation of liver cytochrome P450.

METHODS

The 5-HT2C serotonin receptor agonist CP-809,101 was injected into the ARC for 5 days. The liver cytochrome P450 activity and protein level were measured.

RESULTS

In rats receiving an injection of the 5-HT2C serotonin receptor agonist CP-809,101 into the ARC (1 μg/side) for five days, the activities of CYP2B, CYP2C11 and CYP3A significantly increased corresponding with the elevated enzyme protein level.

CONCLUSIONS

The obtained results suggest that the 5-HT2C serotonin receptor subtype in the ARC is involved in the positive neuroendocrine regulation of cytochrome P450. Further studies are in progress to explain the physiological mechanism which is responsible for the observed regulation of cytochrome P450 by 5-HT2C receptor present in the ARC.

The influence of biological sex and sex hormones on bile acid synthesis and cholesterol homeostasis

Obesity and elevated serum lipids are associated with a threefold increase in the risk of developing atherosclerosis, a condition that underlies stroke, myocardial infarction, and sudden cardiac death. Strategies that aim to reduce serum cholesterol through modulation of liver enzymes have been successful in decreasing the risk of developing atherosclerosis and reducing mortality. Statins, which inhibit cholesterol biosynthesis in the liver, are considered among the most successful compounds developed for the treatment of cardiovascular disease. However, recent debate surrounding their effectiveness and safety prompts consideration of alternative cholesterol-lowering therapies, including increasing cholesterol catabolism through bile acid (BA) synthesis. Targeting the enzymes that convert cholesterol to BAs represents a promising alternative to other cholesterol-lowering approaches that treat atherosclerosis as well as fatty liver diseases and diabetes mellitus. Compounds that modify the activity of these pathways have been developed; however, there remains a lack of consideration of biological sex. This is necessary in light of strong evidence for sexual dimorphisms not only in the incidence and progression of the diseases they influence but also in the expression and activity of the proteins affected and in the manner in which men and women respond to drugs that modify lipid handling in the liver. A thorough understanding of the enzymes involved in cholesterol catabolism and modulation by biological sex is necessary to maximize their therapeutic potential.

Sex differences in the association between perfluoroalkyl acids and liver function in US adolescents: Analyses of NHANES 2013-2016

Perfluoroalkyl acids (PFAAs) are persistent in the environment, highly bio-accumulative in the body, and likely hepatotoxic in humans. There is evidence of sex-specific physiological responses to PFAA exposure. However, epidemiological studies seldom stratify the analyses by sex. Given the high prevalence of liver disease in general population adolescents, this study was designed to determine whether or not there is association between exposure to PFAAs and biomarkers of liver function in adolescent participants of the 2013-2016 National Health and Nutrition Examination Survey, and whether or not such association is sex-specific. Multivariate linear regressions were performed to examine the association between single PFAAs [perfluorooctane sulfonic acid (PFOS); linear form of perfluorooctanoic acid (PFOA); perfluorohexane sulfonic acid (PFHxS); perfluorononanoic acid (PFNA)], and biomarkers of liver function - gamma glutamyltransferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin. Multivariate logistic regressions were performed to estimate adjusted odd ratios (aOR) of elevated ALT, AST and GGT. The study results show that, in females, there was a positive association of the highest PFOA quartile with increased ALT, AST and GGT, and the highest PFNA quartile with increased ALT and AST. Conversely, in male adolescents there was an association of the highest linear PFOA quartile with decreased ALT, and the highest PFNA quartile with ALT and AST. Females had higher odds of clinically-defined elevated ALT with increased PFOA (aOR = 1.79; 95% CI: 1.05, 3.04) or PFNA (aOR = 2.28; 95% CI: 1.08, 2.28), whereas males had decreased odds of clinically-defined elevated ALT with increased n-PFOA (aOR = 0.43; 95% CI: 0.20, 0.93) or PFNA (aOR = 0.5; 95% CI: 0.28, 0.89). In conclusion, there were sex differences in the association between serum PFAA levels and biomarkers of liver function. These results may provide support for analyzing sex-based adverse effects of PFAAs.

Relationship between primary eradication of Helicobacter pylori and drinking habits in women: collaborative research between a pharmacy and a clinic

Helicobacter pylori is a cause of stomach cancer and peptic ulcer. For prevention, improving the eradication rate of H. pylori is crucial. However, the association between eradication and lifestyle of infected patients, including alcohol consumption, remains unclear. We explored associations between failed primary eradication therapy and drinking status by sex. This study involved 356 patients who visited a pharmacy with prescriptions for primary H. pylori eradication therapy. We assessed drinking habits using a questionnaire. Data on patients with failed primary eradication were provided by the nearby local clinic. We performed logistic regression analysis to examine the effect of drinking habit and frequency of drinking on failed primary eradication by sex. The odds ratio of primary eradication failure in female patients with a drinking habit was 3.75 (P = 0.001), but that in male patients was not significant. The odds ratio tended to increase in relation to drinking frequency in women. Frequent consumption of alcohol is not only likely to affect eradication, but also has a large impact on the bodies of women, who are more susceptible than men to the effects of alcohol. Thus, women should take greater care in alcohol consumption.

Identification and Application of Gene Expression Signatures Associated with Lifespan Extension

Several pharmacological, dietary, and genetic interventions that increase mammalian lifespan are known, but general principles of lifespan extension remain unclear. Here, we performed RNA sequencing (RNA-seq) analyses of mice subjected to 8 longevity interventions. We discovered a feminizing effect associated with growth hormone regulation and diminution of sex-related differences. Expanding this analysis to 17 interventions with public data, we observed that many interventions induced similar gene expression changes. We identified hepatic gene signatures associated with lifespan extension across interventions, including upregulation of oxidative phosphorylation and drug metabolism, and showed that perturbed pathways may be shared across tissues. We further applied the discovered longevity signatures to identify new lifespan-extending candidates, such as chronic hypoxia, KU-0063794, and ascorbyl-palmitate. Finally, we developed GENtervention, an app that visualizes associations between gene expression changes and longevity. Overall, this study describes general and specific transcriptomic programs of lifespan extension in mice and provides tools to discover new interventions.

A Novel Self-Emulsifying Drug Delivery System (SEDDS) Based on VESIsorb® Formulation Technology Improving the Oral Bioavailability of Cannabidiol in Healthy Subjects

Cannabidiol (CBD), a phytocannabinoid compound of Cannabis sativa, shows limited oral bioavailability due to its lipophilicity and extensive first-pass metabolism. CBD is also known for its high intra- and inter-subject absorption variability in humans. To overcome these limitations a novel self-emulsifying drug delivery system (SEDDS) based on VESIsorb^® formulation technology incorporating CBD, as Hemp-Extract, was developed (SEDDS-CBD). The study objective was to evaluate the pharmacokinetic profile of SEDDS-CBD in a randomized, double-blind, cross-over design in 16 healthy volunteers under fasted conditions. As reference formulation, the same Hemp-Extract diluted with medium-chain triglycerides (MCT-CBD) was used. CBD dose was standardized to 25 mg. Pharmacokinetic parameters were analyzed from individual concentration-time curves. Single oral administration of SEDDS-CBD led to a 4.4-fold higher C_max and a 2.85-/1.70-fold higher AUC_0–8h/AUC_0–24h compared to the reference formulation. T_max was substantially shorter for SEDDS-CBD (1.0 h) compared to MCT-CBD (3.0 h). Subgroup analysis demonstrated a higher bioavailability in women compared to men. This difference was seen for MCT-CBD while SEDDS-CBD mitigated this gender effect. Overall, SEDDS-CBD showed a significant improvement for all determined pharmacokinetic parameters: increased CBD plasma values (C_max), favorably enhanced bioavailability (AUC) and fast absorption (T_max). No safety concerns were noted following either administration.

Effects of methylparaben, ethylparaben, and propylparaben on life parameters and sex ratio in the marine copepod Tigriopus japonicus

Parabens are used as a preservative substance in a wide range of man-made products causing deleterious effects on aquatic organisms and therefore, the concern of their effects to aquatic organisms has been increased. In this study, acute toxicity of methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) was assessed in the marine copepod Tigriopus japonicus. The acute toxicity assessment resulted in the median lethal concentration (LC50) values of MeP, EtP, and PrP were 29,754, 11,659, and 113 μg/L, respectively, for male and 38,183, 15,371, and 357 μg/L, respectively, for female, indicating the strongest toxicity of PrP, compared to MeP and EtP and the higher sensitivity of males compared to females. Developmental retardation and reproduction rate were also measured under chronic exposure. Furthermore, significant alteration in sex ratio was shown in PrP-exposed group, indicating PrP would have feminization effect in T. japonicus. Here we report different toxicity of three types of parabens and also shows potential estrogenic effects of PrP in T. japonicus.

Disruption of ESR1 alters the expression of genes regulating hepatic lipid and carbohydrate metabolism in male rats

The liver helps maintain energy homeostasis by synthesizing and storing glucose and lipids. Gonadal steroids, particularly estrogens, play an important role in regulating metabolism. As estrogens are considered female hormones, metabolic disorders related to the disruption of estrogen signaling have mostly been studied in females. Estrogen receptor alpha (ESR1) is the predominant receptor in both the male and female liver, and it mediates the hepatic response to estrogens. Loss of ESR1 increases weight gain and obesity in female rats, while reducing the normal growth in males. Although Esr1-/- male rats have a reduced body weight, they exhibit increased adipose deposition and impaired glucose tolerance. We further investigated whether these metabolic disorders in Esr1-/- male rats were linked with the loss of transcriptional regulation by ESR1 in the liver. To identify the ESR-regulated genes, RNA-sequencing was performed on liver mRNAs from wildtype and Esr1-/- male rats. Based on an absolute fold change of ≥2 with a p-value ≤ 0.05, a total of 706 differentially expressed genes were identified in the Esr1-/- male liver: 478 downregulated, and 228 upregulated. Pathway analyses demonstrate that the differentially expressed genes include transcriptional regulators (Cry1, Nr1d1, Nr0b2), transporters (Slc1a2), and regulators of biosynthesis (Cyp7b1, Cyp8b1), and hormone metabolism (Hsd17b2, Sult1e1). Many of these genes are also integral parts of the lipid and carbohydrate metabolism pathways in the liver. Interestingly, certain critical regulators of the metabolic pathways displayed a sexual dimorphism in expression, which may explain the divergent weight gain in Esr1-/- male and female rats despite common metabolic dysfunctions.

Impact of CAR Agonist Ligand TCPOBOP on Mouse Liver Chromatin Accessibility

Activation of the nuclear receptor and transcription factor CAR (Nr1i3) by its specific agonist ligand TCPOBOP (1, 4-bis[2-(3, 5-dichloropyridyloxy)]benzene) dysregulates hundreds of genes in mouse liver and is linked to male-biased hepatocarcinogenesis. To elucidate the genomic organization of CAR-induced gene responses, we investigated the distribution of TCPOBOP-responsive RefSeq coding and long noncoding RNA (lncRNA) genes across the megabase-scale topologically associating domains (TADs) that segment the genome, and which provide a structural framework that functionally constrains enhancer-promoter interactions. We show that a subset of TCPOBOP-responsive genes cluster within TADs, and that TCPOBOP-induced genes and TCPOBOP-repressed genes are often found in different TADs. Further, using DNase-seq and DNase hypersensitivity site (DHS) analysis, we identified several thousand genomic regions (ΔDHS) where short-term exposure to TCPOBOP induces localized changes (increases or decreases) in mouse liver chromatin accessibility, many of which cluster in TADs together with TCPOBOP-responsive genes. Sites of chromatin opening were highly enriched nearby genes induced by TCPOBOP and chromatin closing was highly enriched nearby genes repressed by TCPOBOP, consistent with TCPOBOP-responsive ΔDHS serving as enhancers and promoters that positively regulate CAR-responsive genes. Gene expression changes lagged behind chromatin opening or closing for a subset of TCPOBOP-responsive ΔDHS. ΔDHS that were specifically responsive to TCPOBOP in male liver were significantly enriched for genomic regions with a basal male bias in chromatin accessibility; however, the male-biased response of hepatocellular carcinoma-related genes to TCPOBOP was not associated with a correspondingly male-biased ΔDHS response. These studies elucidate the genome-wide organization of CAR-responsive genes and of the thousands of associated genomic sites where TCPOBOP exposure induces both rapid and persistent changes in chromatin accessibility.

Sex-Biased lncRNAs Inversely Correlate With Sex-Opposite Gene Coexpression Networks in Diversity Outbred Mouse Liver

Sex differences in liver gene expression are determined by pituitary growth hormone secretion patterns, which regulate sex-dependent liver transcription factors and establish sex-specific chromatin states. Hypophysectomy (hypox) identifies two major classes of liver sex-biased genes, defined by their sex-dependent positive or negative responses to pituitary hormone ablation. However, the mechanisms that underlie each hypox-response class are unknown. We sought to discover candidate, regulatory, long noncoding RNAs (lncRNAs) controlling responsiveness to hypox. We characterized gene structures and expression patterns for 15,558 mouse liver-expressed lncRNAs, including many sex-specific lncRNAs regulated during postnatal development or subject to circadian regulation. Using the high natural allelic variance of Diversity Outbred (DO) mice, we discovered tightly coexpressed clusters of sex-specific protein-coding genes (gene modules) in male and female DO liver. Remarkably, many gene modules were strongly enriched for sex-specific genes within a single hypox-response class, indicating that the genetic heterogeneity of DO mice encompasses responsiveness to hypox. Moreover, several distant gene modules were enriched for gene subsets of the same hypox-response class, highlighting the complex regulation of hypox-responsiveness. Finally, we identified eight sex-specific lncRNAs with strong negative regulatory potential, as indicated by their strong negative correlation of expression across DO mouse livers with that of protein-coding gene modules enriched for genes of the opposite sex bias and inverse hypox-response class. These findings reveal an important role for genetic factors in regulating responsiveness to hypox, and present testable hypotheses for the roles of sex-biased liver lncRNAs in controlling the sex-bias of liver gene expression.

Lithium and valproate serum level fluctuations within the menstrual cycle: a systematic review

Some women affected by mood disorders experience mood instability during the premenstrual phase. Assuming that fluctuations in drug serum levels may contribute to the worsening of mood symptoms, we carried out a systematic review of available studies that investigated changes in lithium and valproate levels in relation to menstrual phases. We selected five studies; four of which assessed menstrual fluctuations in lithium serum levels and one in valproate levels. Study samples included women in their fertile age affected by bipolar disorder, epilepsy as well as healthy ones. Preliminary results showed a close relationship between cyclic premenstrual exacerbation of affective symptoms and a significant decrease in lithium levels during the luteal phase, despite stable oral doses, in bipolar women. In healthy women, lithium levels were influenced by neither menstrual cycle phases nor oral contraceptives use. Valproate serum levels in epileptic women showed a small, nonsignificant decline during the mid-luteal phase. Pharmacokinetic sex differences in adsorption, volume distribution, hepatic metabolism, and renal excretion of mood stabilizers have been supposed to partly explain such menstrual serum level fluctuations. A better understanding in this field could help to counteract the distress related to premenstrual phase, improving therapeutic management of mood disorders in women.

Animal and plant factors which affect larkspur toxicosis in cattle: Sex, age, breed, and plant chemotype

Larkspur (Delphinium spp.) poisoning is a long-term problem for cattle grazing on rangelands of western North America. Recent research has shown that both plant and animal-based factors are critical in understanding and mitigating larkspur poisoning in cattle. Non-toxicological factors including sex, age, cattle breed, and plant chemotype affect cattle responses to larkspur. For example, Angus heifers are more susceptible to larkspur intoxication than are steers or bulls. Young cattle appear to be more susceptible to larkspur poisoning than mature animals. Beef breeds of cattle are more susceptible to larkspur intoxication than dairy breeds. In addition to animal factors, plant alkaloid composition (chemotype) affects the potential toxicity for cattle because of differences in the ratios and concentrations of highly toxic N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids compared to less lethal non-MSAL-type alkaloids. Animal- and plant-based factors can provide substantial information to inform livestock producers on management to reduce risk and cattle losses to various larkspur species in western North America.