The effects of gonadal hormones on heroin Self-Administration in male gonadectomized rats.

RATIONALE: Previous studies have shown that gonadal hormones influence opioid self-administration in female rodents, but very few studies have examined these effects in male rodents. OBJECTIVES: The purpose of this study was to examine the effects of chronic hormone treatment on intravenous heroin self-administration in gonadectomized male rats using both physiological and supraphysiological doses of testosterone, estradiol, or progesterone. METHODS: Gonadectomized male rats were surgically implanted with intravenous catheters and trained to self-administer heroin on a fixed ratio (FR1) schedule of reinforcement. Using a between-subjects design, rats were treated daily with testosterone (0.175 or 1.75 mg, sc), estradiol (0.0005 or 0.005 mg, sc), progesterone, (0.0125 or 0.125 mg, sc), or their vehicles. After 14 days of chronic treatment, a dose-effect curve was determined for heroin (0.0003-0.03 mg/kg/infusion) over the course of one week. RESULTS: Neither testosterone nor estradiol altered responding maintained by heroin. In contrast, the high dose of progesterone (0.125 mg) reduced responding maintained by all doses of heroin to saline-control levels. This dose of progesterone did not reduce responding maintained by food on a progressive ratio schedule in either food-restricted or food-sated rats. CONCLUSIONS: These data indicate that exogenous progesterone or a pharmacologically active metabolite selectively decreases heroin intake in male rodents, which may have therapeutic implications for men with opioid use disorder.

Estradiol and Mu opioid-mediated reward: The role of estrogen receptors in opioid use.

Opioid use and opioid use disorder are characterized by sex and gender differences, and some of these differences may be mediated by differences in the hormonal milieu within and across individuals. This review focuses on the role of ovarian hormones, and particularly estradiol, on the endogenous mu opioid receptor system. There is an abundance of data indicating that estradiol influences the activity of endogenous mu opioid peptides, the activation of mu opioid receptors, and the internalization and desensitization of mu opioid receptors. These effects have functional consequences on behaviors mediated by endogenous mu opioid receptor activity and on sensitivity to mu opioid agonists and antagonists. Recent behavioral data suggest these consequences extend to mu opioid reward, and preclinical studies report that estradiol decreases self-administration of mu opioid receptor agonists across a range of experimental conditions. Data collected in human laboratory studies suggest that estradiol may have functionally similar effects in clinical populations, and thus estrogen receptors may be a potential target in the development of novel therapeutics. This review summarizes data from cellular assays to clinical trials to explore how estradiol influences mu opioid receptor activity, as well as potential ways in which estrogen receptors may be targeted to address the problems of opioid use.

Social influence and the likelihood of using cannabis: Role of source physical attractiveness.

The presence of another individual may increase or decrease the likelihood a person will use drugs, depending on factors such as whether the source (i.e., the other individual) is also using drugs. The purpose of this study was to determine whether the physical attractiveness of the source influences the likelihood a person will use cannabis. Heterosexual men and women were recruited via a crowdsourcing platform and asked to rank order the physical attractiveness of 13 opposite-gender people. Participants were then presented with hypothetical scenarios in which they reported the likelihood of engaging in drug use (i.e., "use marijuana") and a nondrug control activity ("enjoy the view" from a private balcony) when they were alone versus in the presence of an opposite-gender person they rated low, moderate, or high in relative physical attractiveness. The likelihood of participating in both drug and nondrug activities increased as a function of the relative physical attractiveness of the other individual (i.e., the source); however, notable gender differences were observed in the likelihood of using cannabis. Women were less likely to use cannabis in the presence of less attractive men relative to using cannabis alone, whereas men were more likely to use cannabis in the presence of more attractive women than using cannabis alone. These data suggest the presence of an opposite-gender person can either inhibit or facilitate drug use depending on the physical attractiveness of the source and gender of the subject. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sequencing of Camelina neglecta, a diploid progenitor of the hexaploid oilseed Camelina sativa.

Camelina neglecta is a diploid species from the genus Camelina, which includes the versatile oilseed Camelina sativa. These species are closely related to Arabidopsis thaliana and the economically important Brassica crop species, making this genus a useful platform to dissect traits of agronomic importance while providing a tool to study the evolution of polyploids. A highly contiguous chromosome-level genome sequence of C. neglecta with an N50 size of 29.1 Mb was generated utilizing Pacific Biosciences (PacBio, Menlo Park, CA) long-read sequencing followed by chromosome conformation phasing. Comparison of the genome with that of C. sativa shows remarkable coincidence with subgenome 1 of the hexaploid, with only one major chromosomal rearrangement separating the two. Synonymous substitution rate analysis of the predicted 34 061 genes suggested subgenome 1 of C. sativa directly descended from C. neglecta around 1.2 mya. Higher functional divergence of genes in the hexaploid as evidenced by the greater number of unique orthogroups, and differential composition of resistant gene analogs, might suggest an immediate adaptation strategy after genome merger. The absence of genome bias in gene fractionation among the subgenomes of C. sativa in comparison with C. neglecta, and the complete lack of fractionation of meiosis-specific genes attests to the neopolyploid status of C. sativa. The assembled genome will provide a tool to further study genome evolution processes in the Camelina genus and potentially allow for the identification and exploitation of novel variation for Camelina crop improvement.

Methodologies and Emerging Technologies for the Evaluation of the Hematopoietic System.

Hematology and bone marrow analysis is central to our understanding of the hematopoietic system and how it responds to insults, and this session presented during the 2022 STP symposium provided a review of current and novel approaches for the evaluation of the hematopoietic system in the context of nonclinical investigations. This publication summarizes the information presented on novel approaches for evaluation of the hematopoietic system using automated hematology analyzers, including details around the quantitative assessment of bone marrow cell suspensions as well as introducing several newly available hematology parameters. It was followed by a discussion on intravital microscopy and live cell imaging and how these methods can assist with de-risking hematopoiesis-associated safety concerns, and a review of recent assays using artificial intelligence for the evaluation of bone marrow.

Modulation of morphine physical dependence and discriminative stimulus effects by ovarian hormones: Role of estradiol.

Ovarian hormones influence the activity of endogenous opioids, and exogenous administration of estradiol reduces opioid intake and opioid seeking in animal models of opioid reward and reinforcement. The purpose of this study was to examine the effects of ovarian hormones on the discriminative stimulus effects of morphine and naloxone-precipitated opioid withdrawal. To this end, separate groups of ovariectomized female rats were trained to discriminate the stimulus effects of either 3.0 or 10 mg/kg morphine, and substitution tests were conducted with estradiol or progesterone alone and in combination with morphine. At the conclusion of discrimination testing, rats were treated chronically with estradiol, progesterone, or their combination, and challenged with naloxone to measure opioid-like withdrawal symptoms. Finally, the effects of estradiol, progesterone, and their combination were examined on naloxone-precipitated withdrawal in morphine-dependent rats. Neither estradiol nor progesterone substituted for the morphine discriminative stimulus, but estradiol significantly increased the potency of morphine in rats trained to discriminate 10 mg/kg but not 3 mg/kg morphine. When administered chronically, neither hormone nor their combination produced an opioid-like withdrawal syndrome following a naloxone challenge. Acute administration of estradiol, but not progesterone or a combination of estradiol and progesterone, significantly reduced naloxone-precipitated weight loss in morphine-dependent rats. These data indicate that estradiol influences the behavioral effects of morphine, possibly by increasing endogenous tone at mu opioid receptors.

Does mismatch negativity have utility for NMDA receptor drug development in depression?

Rapid antidepressant effects associated with ketamine have shifted the landscape for the development of therapeutics to treat major depressive disorder (MDD) from a monoaminergic to glutamatergic model. Treatment with ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, may be effective, but has many non-glutamatergic targets, and clinical and logistical problems are potential challenges. These factors underscore the importance of manipulations of binding mechanics to produce antidepressant effects without concomitant clinical side effects. This will require identification of efficient biomarkers to monitor target engagement. The mismatch negativity (MMN) is a widely used electrophysiological signature linked to the activity of NMDA receptors (NMDAR) in humans and animals and validated in pre-clinical and clinical studies of ketamine. In this review, we explore the flexibility of the MMN and its capabilities for reliable use in drug development for NMDAR antagonists in MDD. We supplement this with findings from our own research with three distinct NMDAR antagonists. The research described illustrates that there are important distinctions between the mechanisms of NMDAR antagonism, which are further crystallized when considering the paradigm used to study the MMN. We conclude that the lack of standardized methodology currently prevents MMN from being ready for common use in drug discovery. Clinical trial registration: This manuscript describes data collected from the following National Institutes of Health (NIH) and Veterans Affairs (VA) studies: AV-101, NCT03583554; lanicemine, NCT03166501; ketamine, NCT02556606.

The effects of artificially induced proestrus on heroin intake: A critical role for estradiol.

Heroin intake decreases markedly during proestrus in normally cycling female rats; however, it is not known whether estradiol, progesterone, or both hormones are responsible for these decreases in heroin intake. The purpose of the present study was to examine the roles of estradiol and progesterone in heroin intake by artificially inducing a proestrus state in ovariectomized rats. To this end, ovariectomized female rats were implanted with intravenous catheters and trained to self-administer heroin (0.0075 mg/kg/infusion) on a fixed ratio (FR1) schedule of reinforcement. After 1 week of training, rats were tested at weekly intervals with estradiol (0.005 mg, sc) or vehicle 22 hr before a test session and progesterone (0.125 mg, sc) or vehicle 0.5 hr before a test session to artificially mimic the naturally occurring hormone concentrations characteristic of late proestrus. Administration of estradiol 22 hr prior to testing and progesterone 0.5 hr prior to testing significantly reduced heroin intake relative to the previous training day and vehicle control. It is interesting that this same effect was observed when only estradiol, but not progesterone, was administered. These data suggest that estradiol but not progesterone is responsible for the proestrus-induced decreases in heroin intake previously reported in normally cycling female rats. These findings differ from those reported previously with stimulants and suggest that estrogen-based pharmacotherapies may be of value to women with opioid use disorder. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The effects of chronic estradiol treatment on opioid self-administration in intact female rats.

Heroin intake decreases significantly during proestrus in normally cycling female rats, and this effect is mediated by endogenous estradiol but not endogenous progesterone. The purpose of this study was to determine whether chronic administration of exogenous estradiol decreases intake of the semi-synthetic opioid, heroin, and the fully synthetic opioid, remifentanil, in intact female rats. Normally cycling female rats were implanted with intravenous catheters and trained to self-administer heroin on a fixed ratio (FR1) schedule of reinforcement. Rats were treated chronically with daily administration of either a low dose of estradiol (0.5 mcg, sc), a high dose of estradiol (5.0 mcg, sc), or vehicle (peanut oil, sc). After two weeks of heroin self-administration training, dose-effect curves were determined for both heroin and remifentanil. Chronic administration of estradiol non-significantly decreased heroin intake and significantly decreased remifentanil intake. Estradiol-induced decreases in remifentanil intake were dose-dependent, characterized by large effect sizes, and greatest in rats treated with the high dose of estradiol. These data indicate that chronic estradiol administration decreases opioid intake in intact female rats with medium to large effect sizes across opioids. These findings suggest that estrogen-based pharmacotherapies may represent a novel treatment approach for women with opioid use disorder.

Screening For Bone Marrow Cellularity Changes in Cynomolgus Macaques in Toxicology Safety Studies Using Artificial Intelligence Models.

Many compounds affect the cellularity of hematolymphoid organs including bone marrow. Toxicologic pathologists are tasked with their evaluation as part of safety studies. An artificial intelligence (AI) tool could provide diagnostic support for the pathologist. We looked at the ability of a deep-learning AI model to evaluate whole slide images of macaque sternebrae to identify and enumerate bone marrow hematopoietic cells. The AI model was trained and able to differentiate the hematopoietic cells from the other sternebrae tissues. We compared the model to severity scores in a study with decreased hematopoietic cellularity. The mean cells/mm2 from the model was lower for each increase in severity score. The AI model was trained by 1 pathologist, providing proof of concept that AI model generation can be fast and agile, without the need of a cross disciplinary team and significant effort. We see great potential for the role of AI-based bone marrow screening.

Modulation of heroin intake by ovarian hormones in gonadectomized and intact female rats.

RATIONALE: Heroin intake decreases during the proestrus phase of the estrous cycle in female rats. Circulating concentrations of both estradiol and progesterone peak during proestrus, and it is not known which of these hormones, or their combination, are responsible for these effects. OBJECTIVES: The purpose of this study was to determine the effects of estradiol, progesterone, and their combination on heroin self-administration in female rats. METHODS: In Experiment 1, the estrous cycle of intact female rats was tracked daily. If a rat was in proestrus, either the estrogen receptor antagonist, raloxifene, the progesterone receptor antagonist, mifepristone, or their combination was administered 30 min prior to a heroin self-administration session. In Experiment 2, separate groups of ovariectomized female rats were treated chronically with exogenous estradiol, progesterone, estradiol + progesterone, or vehicle, and heroin intake was examined over a 100-fold dose range. RESULTS: In Experiment 1, raloxifene, but not mifepristone, significantly blocked proestrus-associated decreases in heroin intake. In Experiment 2, estrogentreated rats self-administered less heroin than any other group and significantly less heroin than rats treated with progesterone. CONCLUSIONS: These data suggest that (1) estradiol but not progesterone is responsible for proestrus-associated decreases in heroin intake and (2) estradiol decreases heroin intake relative to progesterone. These data differ from those reported previously with stimulants and suggest that estrogen-based pharmacotherapies may be of value to women with opioid use disorder.

Mechanosensing through Direct Binding of Tensed F-Actin by LIM Domains.

Mechanical signals transmitted through the cytoplasmic actin cytoskeleton must be relayed to the nucleus to control gene expression. LIM domains are protein-protein interaction modules found in cytoskeletal proteins and transcriptional regulators. Here, we identify three LIM protein families (zyxin, paxillin, and FHL) whose members preferentially localize to the actin cytoskeleton in mechanically stimulated cells through their tandem LIM domains. A minimal actin-myosin reconstitution system reveals that representatives of all three families directly bind F-actin only in the presence of mechanical force. Point mutations at a site conserved in each LIM domain of these proteins disrupt tensed F-actin binding in vitro and cytoskeletal localization in cells, demonstrating a common, avidity-based mechanism. Finally, we find that binding to tensed F-actin in the cytoplasm excludes the cancer-associated transcriptional co-activator FHL2 from the nucleus in stiff microenvironments. This establishes direct force-activated F-actin binding as a mechanosensing mechanism by which cytoskeletal tension can govern nuclear localization.

Chronic Rhinotillexomania Leading to Multiple Infectious Sequelae in a 66-Year-Old Female.

Rhinotillexomania, more commonly known as nose-picking, is a body-focused repetitive behavior that involves compulsive picking of the nares. While nose-picking in general is a common and largely unharmful practice worldwide, severe complications from chronic nose-picking do exist. This case highlights a 66-year-old female with a longstanding history of nose-picking and nose blowing who presented to the emergency department with acute delirium and various bodily complaints. She was subsequently admitted multiple times for recurrent sepsis, meningitis, endocarditis, cystitis, and discitis with each culture positive for methicillin-sensitive Staphylococcus aureus (MSSA) with identical antibiotic sensitivities. Further imaging failed to reveal an underlying greater pathology. Intranasal swab revealed identical culture and sensitivity results as previous blood, CSF, and urine cultures and was thus hypothesized to be the source of infection. This case aims to elucidate the harmful effects of nose-picking as well as the importance of prevention, diagnosis, and management.

Putative Gonadotropin-Releasing Hormone Agonist Therapy and Dementia: An Application of Medicare Hospitalization Claims Data.

BACKGROUND: Estrogen and hormone replacement therapies to reduce Alzheimer's disease (AD) have yielded conflicting results. However, this study proposes that the well-characterized increase in serum gonadotropins following menopause or andropause are accountable for the increased risk of developing AD among the elderly population. OBJECTIVE: To determine the role of gonadotropins in the development of AD and investigate gonadotropin-releasing hormone (GnRH) agonist therapy as a potential preventative and/or disease-modifying approach to AD management. METHODS: Male Medicare beneficiaries aged 67 to 75 and hospitalized with prostate cancer (n = 115,789) were compared to three control groups: men of the same demographics undergoing a cholecystectomy (n = 97,267), herniorrhaphy (n = 68,778), or transurethral prostatectomy (n = 267,691). A proportion of the patients hospitalized with prostate cancer were assumed to have low concentrations of serum gonadotropins and sex steroids as a result of GnRH agonist therapy, while those in the control groups were assumed to have elevated gonadotropin but lowered sex steroid levels that are associated with andropause in this age group. RESULTS: The rates of development of select diagnoses of dementia, including AD, over a twelve-year follow-up period following surgery. When compared to control patients, men hospitalized with prostate cancer have a protection against dementia after twelve years of follow-up, with relative risks ranging from 0.48 to 0.83. CONCLUSION: Patients with prostate cancer are treated with the GnRH analogue leuprolide acetate, our data suggest that leuprolide acetate may be therapeutic for AD via its downregulation of serum gonadotropins.

Resistance exercise decreases heroin self-administration and alters gene expression in the nucleus accumbens of heroin-exposed rats.

RATIONALE: Preclinical studies consistently report that aerobic exercise decreases drug self-administration and other forms of drug-seeking behavior; however, relatively few studies have examined other types of physical activity. OBJECTIVES: The purpose of the present study was to examine the effects of resistance exercise (i.e., strength training) on heroin self-administration and mRNA expression of genes known to mediate opioid reinforcement and addictive behavior in the nucleus accumbens (NAc) of heroin-exposed rats. METHODS: Female rats were obtained during late adolescence and divided into two groups. Resistance exercise rats were trained to climb a vertical ladder wearing a weighted vest; sedentary control rats were placed repeatedly on the ladder oriented horizontally on its side. All rats were implanted with intravenous catheters and trained to self-administer heroin on a fixed ratio (FR1) schedule of reinforcement. mRNA expression in the NAc core and shell was examined following behavioral testing. RESULTS: Resistance exercise significantly decreased heroin self-administration, resulting in a downward shift in the dose-effect curve. Resistance exercise also reduced mRNA expression for mu opioid receptors and dopamine D1, D2, and D3 receptors in the NAc core. Resistance exercise increased mRNA expression of dopamine D5 receptors in the NAc shell and increased mRNA expression of brain-derived neurotrophic factor (exons I, IIB, IIC, IV, VI, IX) in the NAc core. CONCLUSIONS: These data indicate that resistance exercise decreases the positive reinforcing effects of heroin and produces changes in opioid and dopamine systems in the NAc of heroin-exposed rats.

Exercise as a Sex-Specific Treatment for Substance Use Disorder.

PURPOSE OF REVIEW: Exercise is a promising treatment for substance use disorder that may reduce withdrawal symptoms and prevent relapse. In this review, we discuss recent evidence from clinical and preclinical studies for its efficacy, from a behavioral to a molecular level, in order to understand the exercise conditions that lead to beneficial effects. We also highlight the few recent findings of sex-specific differences. RECENT FINDINGS: Clinical and preclinical findings show that exercise decreases withdrawal symptoms, including craving, in both males and females. Evidence from clinical studies support the efficacy of exercise to prevent relapse to smoking, although further research is needed to examine sex differences, establish long-term efficacy, and to determine if effects extend to other substance use disorders. Preclinical findings also support the potential utility of exercise to prevent relapse with evidence suggesting that its efficacy is enhanced in males, and mediated by blocking drug-induced adaptations that occur during early abstinence. SUMMARY: Sex differences and timing of exercise availability during abstinence should be considered in future studies examining exercise as an intervention for relapse. A better understanding of the neurobiological mechanisms underlying the efficacy of exercise to reduce withdrawal symptoms and prevent relapse is needed to guide its development as a sex-specific treatment.

Chronic Activation of γ2 AMPK Induces Obesity and Reduces ß Cell Function.

Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK γ2 subunit, exhibit ghrelin signaling-dependent hyperphagia, obesity, and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation throughout all tissues can have adverse metabolic consequences, with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease.

The effects of physical activity on impulsive choice: Influence of sensitivity to reinforcement amount and delay.

Impulsive choice is a diagnostic feature and/or complicating factor for several psychological disorders and may be examined in the laboratory using delay-discounting procedures. Recent investigators have proposed using quantitative measures of analysis to examine the behavioral processes contributing to impulsive choice. The purpose of this study was to examine the effects of physical activity (i.e., wheel running) on impulsive choice in a single-response, discrete-trial procedure using two quantitative methods of analysis. To this end, rats were assigned to physical activity or sedentary groups and trained to respond in a delay-discounting procedure. In this procedure, one lever always produced one food pellet immediately, whereas a second lever produced three food pellets after a 0, 10, 20, 40, or 80-s delay. Estimates of sensitivity to reinforcement amount and sensitivity to reinforcement delay were determined using (1) a simple linear analysis and (2) an analysis of logarithmically transformed response ratios. Both analyses revealed that physical activity decreased sensitivity to reinforcement amount and sensitivity to reinforcement delay. These findings indicate that (1) physical activity has significant but functionally opposing effects on the behavioral processes that contribute to impulsive choice and (2) both quantitative methods of analysis are appropriate for use in single-response, discrete-trial procedures.

A randomized, placebo-controlled pilot trial of the delta opioid receptor agonist AZD2327 in anxious depression.

RATIONALE: Patients with anxious major depressive disorder (AMDD) have more severe symptoms and poorer treatment response than patients with non-AMDD. Increasing evidence implicates the endogenous opioid system in the pathophysiology of depression. AZD2327 is a selective delta opioid receptor (DOR) agonist with anxiolytic and antidepressant activity in animal models. OBJECTIVE: This double-blind, parallel group design, placebo-controlled pilot study evaluated the safety and efficacy of AZD2327 in a preclinical model and in patients with AMDD. METHODS: We initially tested the effects of AZD2327 in an animal model of AMDD. Subsequently, 22 subjects with AMDD were randomized to receive AZD2327 (3 mg BID) or placebo for 4 weeks. Primary outcome measures included the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A). We also evaluated neurobiological markers implicated in mood and anxiety disorders, including vascular endothelial growth factor (VEGF) and electroencephalogram (EEG). RESULTS: Seven (54 %) patients responded to active drug and three (33 %) responded to placebo. No significant main drug effect was found on either the HAM-D (p = 0.39) or the HAM-A (p = 0.15), but the HAM-A had a larger effect size. Levels of AZ12311418, a major metabolite of AZD2327, were higher in patients with an anti-anxiety response to treatment compared to nonresponders (p = 0.03). AZD2327 treatment decreased VEGF levels (p = 0.02). There was a trend (p < 0.06) for those with an anti-anxiety response to have higher EEG gamma power than nonresponders. CONCLUSION: These results suggest that AZD2327 has larger potential anxiolytic than antidepressant efficacy. Additional research with DOR agonists should be considered.

Antibodies against hemolysin and cytotoxic necrotizing factor type 1 (CNF1) reduce bladder inflammation in a mouse model of urinary tract infection with toxigenic uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) is the leading cause of cystitis. Cytotoxic necrotizing factor 1 (CNF1) and hemolysin (Hly) are toxins made by approximately 50% of UPEC isolates. CNF1 and Hly contribute to the robust inflammatory response in the bladders of mice challenged with UPEC strain CP9. We hypothesized that antibodies against CNF1 and/or Hly would reduce cystitis caused by CP9. To test this theory, we immunized female C3H/HeOuJ mice subcutaneously with a genetically derived Hly toxoid or genetically derived CNF1 toxoid plus sublethal doses of CNF1. We collected serum and observed increasing titers of specific and neutralizing antibodies against Hly or CNF1 over time. We challenged the mice intraurethrally with CP9 and euthanized them 24 h later. We observed 10-fold lower bacterial titers in the urine of Hly-immunized mice than in that of sham-immunized mice but no difference in kidney bacterial titers. Immunized mice also exhibited significantly less cystitis than sham-immunized mice. In CNF1-vaccinated mice, we detected neither a difference in urine or kidney bacterial titers nor a reduction in the severity of cystitis versus that of sham-immunized mice. We then passively administered an anti-CNF1 monoclonal antibody intraperitoneally to female C3H/HeOuJ mice prior to intraurethral challenge with CP9. Upon challenge, we noted no difference in colonization of the urine or kidney; however, cystitis was reduced significantly in mice treated with the anti-CNF1 antibody versus that in the bladders of mice given an isotype control antibody. Taken together, our data demonstrate that antibodies against CNF1 or Hly reduce the bladder pathology caused by UPEC.