Biology subjects

Ricke, W. A.

Publications and source records attributed to Ricke, W. A..

11 recordsLinked to original sources

bioRxiv2026

Amyloid-beta is present in the spinal cord of APP/PS1 mice and may contribute to neuropathology manifesting as lower urinary tract dysfunction

Urinary incontinence (UI) is a common and debilitating comorbidity in Alzheimers disease (AD), yet its underlying pathophysiology remains poorly defined. While UI in dementia has traditionally been attributed to functional impairment, emerging clinical and urodynamic data suggest that neurologic mechanisms may contribute to lower urinary tract dysfunction in this population. Here, we investigated urinary function and neuropathological changes in aged APP/PS1 mice (AD mice), a widely used model of amyloid pathology. Using functional voiding assays, we identified a pattern of urinary dysfunction characterized by increased urinary frequency, small-volume voiding, shortened void duration, and reduced bladder compliance in the absence of bladder outlet obstruction or gross changes in bladder or prostate morphology. These findings are most consistent with a storage-phase abnormality accompanied by impaired voiding coordination rather than classic detrusor overactivity or underactivity. We examined spinal cord and peripheral components involved in bladder innervation and identified amyloid-beta deposition throughout the thoracolumbar and lumbosacral spinal cord, dorsal root ganglia, ventral roots, cauda equina, and associated meningeal structures in AD mice. Importantly, amyloid deposition was accompanied by reduced expression of vesicular acetylcholine transporter and decreased neuronal activation in bladder-innervating pathways, without evidence of increased apoptosis. Taken together, these data demonstrate that AD mice develop a mixed lower urinary tract dysfunction phenotype associated with amyloid-beta deposition and altered neuronal signaling within the spinal cord and peripheral micturition pathways. These findings support a neurogenic contribution to urinary dysfunction in AD and highlight the spinal cord as a novel site of pathology that may influence urinary symptoms in Alzheimers dementia.

neuroscience↗

bioRxiv2026

Profiling crystal engineered ligands for targeting treatment resistant androgen receptors

Prostate cancer (PCa) is one of the principal contributors to health burden in the aging male population. PCa develops through dysregulation of androgen receptor (AR) signaling pathways. Despite improvements in diagnostic techniques and interventions, no pharmacological measures with long term efficacy have been established once PCa advances to castration resistant prostate cancer (CRPC). To circumvent this issue, tetra-aryl cyclobutanes (CBs) have been proposed as structurally distinct compounds with a mechanism of action differing from traditional androgen receptor signaling inhibitor (ARSIs). Here, we apply principles of crystal engineering and solid state synthesis to expand the class of CBs through strategic derivatization. The synthesis of the CB occurs quantitatively, producing no side products and eliminating the need for product purification. We demonstrate how head-to-tail stacking interactions of halo-pyrimidine rings can be exploited to stack and align unsymmetrical alkenes to undergo [2+2] photodimerization to generate the CB in the solid state. We examine the structure-function relationships of CBs in vitro by profiling AR mediated transcriptional activity, receptor translocation, and cell viability. Moreover, we explore and identify putative binding interactions within CB/AR complexes and establish an adaptive ligand-binding potential using molecular docking platforms. In total, our data suggests that CBs have unexploited therapeutic potential in CRPC and that green chemistry and crystal engineering principles offer a unique route to generating these drug candidates.

molecular biology↗

bioRxiv2025

Spoti-find: A novel, open-source void spot assay image analysis tool

The void spot assay (VSA) is a widely used, non-invasive method for evaluating urinary behavior in rodents, but existing analysis tools are limited in scope, throughput, or accessibility. We developed Spoti-find, a stand-alone, open-source VSA image analysis application that introduces novel, biologically meaningful metrics including void circularity, distance to paper edge, and volume-based binning into primary, micro-, and nanovoids. Designed with usability in mind, Spoti-find features a graphical interface that enables manual or semi-automated spot identification, adjustable thresholds, and streamlined data export without the need for coding expertise. We validated Spoti-find across diverse datasets, showing strong inter-user consistency, sensitivity to known phenotypes in aging and disease models, and accuracy in capturing novel parameters while demonstrating high agreement with existing tools. By capturing behavioral context and spatial morphology in voiding patterns, Spoti-find expands the interpretive power of VSA and provides a flexible, user-friendly platform for phenotyping urinary dysfunction in preclinical studies.

physiology↗

bioRxiv2025

Lifelong restriction of dietary valine has sex-specific benefits for health and lifespan in mice

Dietary protein is a key regulator of metabolic health in humans and rodents. Many of the benefits of protein restriction are mediated by reduced intake of dietary branched-chain amino acids (BCAAs; leucine, valine and isoleucine), and restriction of the BCAAs is sufficient to extend healthspan and lifespan in mice. While the BCAAs have often been considered as a group, it has become apparent that they have distinct metabolic roles, and we recently found that restriction of isoleucine is sufficient to extend the healthspan and lifespan of male and female mice. Here, we test the effect of lifelong restriction of the BCAA valine on healthy aging. We find that valine restriction (Val-R) improves metabolic health in C57BL/6J mice, promotes leanness and glycemic control across ages, and reduces frailty, cancer prevalence, and senescent cell burden in multiple tissues in both sexes. Val-R reduces glial activation in the brain in a male-specific manner, and extends the lifespan of male, but not female, mice by 23%. To investigate the molecular mechanisms engaged by Val-R with aging, we conducted multi-tissue transcriptional profiling and gene network analysis. While Val-R had a greater molecular impact in the liver, muscle, and brown adipose tissue of females, the enrichment of genes associated with phenotypic traits was stronger in males. Assessing novel gene relationships across tissues, we identified a liver gene module enriched in mitochondrial-related pathways as a central hub. Assessing mitochondrial function, we identified a Val-R-induced male-specific increase in mitochondrial respiration. Our results demonstrate for the first time that Val-R improves multiple aspects of healthspan in mice of both sexes and extends lifespan in males, and suggests that interventions that mimic Val-R may have translational potential for aging and age-related diseases.

physiology↗

bioRxiv2025

Ex vivo high-resolution nano-computed tomography imaging reveals spatial architecture of the adult male mouse lower urogenital tract

Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms/dysfunction (LUTS/LUTD) in aging men. Over the past 30 years, the prevalence of BPH has increased by 122%, rising from 50.7 million cases in 1990 to 112.5 million in 2021. It is expected that this number will continue to rise over the next 15 years with the global aging population. Although mouse models are invaluable for studying human disease, gross anatomical differences between human and murine prostates complicate their translational relevance for BPH/LUTS research. The purpose of this study was to develop and validate a nanoCT-based imaging approach to enable detailed anatomical analysis of the murine lower urinary tract, with the dual goals of advancing tools for LUTD research and improving the translational relevance of mouse models to human prostate disease. Advancements in nano-computed tomography (nanoCT) have enabled high-resolution characterization of murine organ anatomy, providing new insights into how morphological differences contribute to pathology. To accomplish this, whole lower urogenital tracts from 8-week-old healthy male C57BL/6J mice and microdissected urethras were imaged on a v|tome|x M or nanotom M nano-CT system, respectively. Images were processed for 2D segmentation and subsequent 3D reconstruction using DragonFly 3D World software. Our approach enabled high-resolution visualization and characterization of the murine lower urogenital tract, including the urinary bladder, prostate lobes, seminal vesicles, and ductus deferens, as well as the microscopic ductal architecture of the prostatic urethra. The resulting 3D reconstructions preserved native anatomical relationships and allowed for comparisons between murine and human prostate anatomy. Together, these findings establish a method that can be used for assessing anatomical and morphological changes associated with LUTD development, while also highlighting key anatomical similarities that enhance the translational relevance of mouse models for human prostate disease.

pathology↗

bioRxiv2025

Amyloid-beta deposition and reduced drainage at the cribriform plate lymphatics in APP/PS1 mouse model of Alzheimer's Disease

Alzheimers disease (AD) is the most common cause of dementia, leading to substantial personal, economic, and medical costs to patients and society; it is characterized by the build-up of toxic amyloid-beta (A{beta}) and hyperphosphorylated tau. It is crucial to the health of the brain that these proteins are processed or drained effectively, but mounting research has shown that in AD pathology there is dysfunction in the ability of the brain to effectively clear pathological A{beta} and tau. In this report, we detail the involvement of one important brain drainage pathway and potential site of A{beta} clearance, the cribriform plate lymphatics, in 24-month old APP/PS1 mice. We show that cerebrospinal fluid (CSF) efflux is decreased across the cribriform plate area utilizing multiple methods. Moreover, we demonstrate that A{beta} aggregates at the cribriform plate - coating surface of olfactory bulbs (OB), olfactory nerve (ON) bundles, and cribriform plate lymphatic endothelial cells (cpLECs). At 24-months, APP/PS1 mice have increased CD45+ cell infiltration and decreased LYVE-1+ vessel area at the cribriform plate, suggesting local inflammation and lymphatic atrophy. Additionally, cpLECs have higher expression of caspase-3 suggesting the decreased LYVE-1 area is due to cellular toxicity resulting in apoptosis. This study demonstrates that the cribriform plate is an important area for further research elucidating its contribution to AD disease pathogenesis.

neuroscience↗

bioRxiv2022

Steroid hormone imbalance drives macrophage infiltration and Spp1/osteopontin+ foam cell differentiation in the prostate

Benign Prostatic Hyperplasia (BPH) occurs progressively with aging in men and drives deteriorating symptoms collectively known as Lower Urinary Tract Symptoms (LUTS). Age associated changes in circulating steroid hormones, and prostate inflammation have been postulated in the etiology of BPH/LUTS. The link between hormones and inflammation in the development of BPH/LUTS is conflicting because they may occur independently or as sequential steps in disease pathogenesis. This study aimed to decipher the prostatic immune landscape in a mouse model of lower urinary tract dysfunction (LUTD). Steroid hormone imbalance was generated by the surgical implantation of testosterone (T) and estradiol (E2) pellets to male C57BL/6J mice and gene expression analysis was performed on ventral prostates (VP). These experiments identified an increase in the expression of macrophage markers and Spp1/osteopontin (OPN). Localization studies of OPN pinpointed that OPN+ macrophages travel to the prostate lumen and transition into lipid accumulating foam cells. We also observed a significantly increased number of tissue macrophages in the VP which was prevented in OPN knockout (OPN-KO) mice. In contrast, mast cells, but not macrophages, were significantly elevated in the dorsal prostate of T+E2 treated mice which was diminished in OPN-KO mice. Steroid hormone implantation progressively increased urinary frequency, which was ameliorated in OPN-KO mice. Our study underscores the role of age associated steroid hormone imbalances as a mechanism of expanding the prostatic macrophage population, their luminal translocation and foam cell differentiation.

pathology↗

bioRxiv2022

Dietary restriction of isoleucine increases healthspan and lifespan of genetically heterogeneous mice

Low protein (LP) diets promote health and longevity in diverse species. Although the precise components of an LP diet that mediate its beneficial effects have not been defined, reducing dietary levels of the three branched-chain amino acids (BCAAs) leucine, isoleucine and valine promotes metabolic health in both sexes, and increases lifespan while reducing frailty in male, but not female, C57BL/6J mice. Each BCAA has unique metabolic effects, and we recently showed that restriction of isoleucine is both sufficient to promote metabolic health and required for the metabolic benefits of an LP diet in male C57BL/6J mice. Here, we tested the hypothesis that specifically restricting isoleucine could promote healthy aging in genetically heterogenous UM-HET3 mice. We find that a reduced isoleucine diet improves the metabolic health of both young and old HET3 mice, promoting leanness and glycemic control. Restriction of isoleucine starting in adult, 6 month old HET3 mice reprograms hepatic metabolism in a way distinct from an LP diet. Finally, we find that a reduced isoleucine diet reduces frailty and extends the lifespan of both male and female HET3 mice, but to a much greater degree in males. Our results demonstrate that restricting dietary isoleucine can increase health span and longevity in a genetically diverse population of mice, and suggests that reducing dietary levels of isoleucine may have great potential as a geroprotective intervention.

physiology↗

bioRxiv2021

OSTEOPONTIN DEFICIENCY LEADS TO THE RESOLUTION OF PROSTATIC FIBROSIS AND INFLAMMATION

Fibrogenic and inflammatory processes in the prostate are linked to the development of lower urinary tract symptoms (LUTS) in men. Our previous studies identified that osteopontin (OPN), a pro-fibrotic cytokine, is abundant in the prostate of men with LUTS and its secretion is stimulated by inflammatory cytokines potentially to drive fibrosis. This study investigates whether the lack of OPN ameliorates inflammation and fibrosis in the mouse prostate. We instilled uropathogenic E. coli (UTI89) or saline (control) transurethrally to C57BL/6J (WT) or Spp1tm1Blh/J (OPN-KO) mice and collected the prostates one or 8 weeks later. We found that OPN mRNA and protein expression were significantly induced by E. coli-instillation in the dorsal prostate (DP) after one week in WT mice. Deficiency in OPN expression led to decreased inflammation and fibrosis and the prevention of urinary dysfunction after 8 weeks. RNAseq analysis identified that E. coli-instilled WT mice expressed increased levels of inflammatory and fibrotic marker RNAs compared to OPN-KO mice including Col3a1, Dpt, Lum and Mmp3 which were confirmed by RNAscope. Our results indicate that OPN is induced by inflammation and prolongs the inflammatory state; genetic blockade of OPN accelerates recovery after inflammation, including a resolution of prostate fibrosis.

pathology↗

bioRxiv2019

Prostatic osteopontin expression is associated with symptomatic benign prostatic hyperplasia

BackgroundMale lower urinary tract symptoms (LUTS) occur in more than half of men above 50 years of age. LUTS were traditionally attributed to benign prostatic hyperplasia (BPH) and therefore the clinical terminology often use LUTS and BPH interchangeably. More recently, LUTS were also linked to fibrogenic and inflammatory processes. We tested whether osteopontin (OPN), a pro-inflammatory and pro-fibrotic molecule, is increased in symptomatic BPH. We also tested whether prostate epithelial and stromal cells secrete OPN in response to pro-inflammatory stimuli and identified downstream targets of OPN in prostate stromal cells. MethodsImmunohistochemistry was performed on prostate sections obtained from the transition zone (TZ) of patients who underwent surgery (Holmium laser enucleation of the prostate) to relieve LUTS i.e. surgical BPH (S-BPH) or patients who underwent radical prostatectomy to remove low-grade prostate cancer (incidental BPH, I-BPH). Images of stained tissue sections were captured with a Nuance Multispectral Imaging system and histoscore, as a measure of OPN staining intensity, was determined with inForm software. OPN protein abundance was determined by Western blot. The ability of prostate cells to secrete osteopontin in response to IL-1{beta} and TGF-{beta}1 was determined in stromal (BHPrS-1) and epithelial (NHPrE-1 and BHPrE-1) cells by ELISA. qPCR was used to measure gene expression changes in these cells in response to OPN. ResultsOPN immunostaining (p=0.0107) and protein levels were more abundant in S-BPH than I-BPH. Staining was distributed across all cell types with highest levels in epithelial cells. Multiple OPN protein variants were identified in immortalized prostate stromal and epithelial cells. TGF-{beta}1 stimulated OPN secretion by NHPrE-1 cells and both IL-1{beta} and TGF-{beta}1 stimulated OPN secretion by BHPrS-1 cells. Interestingly, recombinant OPN increased the mRNA expression of CXCL1, CXCL2, CXCL8, PTGS2 and IL6 in BHPrS-1, but not in epithelial cell lines. ConclusionsOPN is more abundant in prostates of men with S-BPH compared to men with I-BPH. OPN secretion is stimulated by pro-inflammatory cytokines, and OPN acts directly on stromal cells to drive the synthesis of pro-inflammatory mRNAs. Pharmacological manipulation of prostatic OPN may have the potential to reduce LUTS by inhibiting both inflammatory and fibrotic pathways.

pathology↗

bioRxiv2019

Factors Driving Unique Urination Phenotypes of Male and Female 9-week-old C57BL/6J Mice

Laboratory mice are used to identify causes of urinary dysfunction including prostate-related mechanisms of Lower Urinary Tract Symptoms (LUTS). Effective use of mice for this purpose requires a clear understanding of molecular, cellular, anatomical, and endocrine contributions to voiding function. Whether the prostate influences baseline voiding function has not been specifically evaluated, in part because most methods that alter prostate mass also change circulating testosterone concentrations. We performed void spot assay and cystometry to establish a multi-parameter \"baseline\" of voiding function in intact male and female 9-week-old (adult) C57BL/6J mice. We then compared voiding function in intact male mice to that of castrate males, males (and females) treated with the steroid five alpha reductase inhibitor finasteride, or males harboring alleles (Pbsn4cre/+;R26RDta/+) that significantly reduce prostate lobe mass by depleting prostatic luminal epithelial cells. We evaluated aging-related changes in male urinary voiding. We also treated intact male, castrate male, and female mice with exogenous testosterone to determine the influence of androgen on voiding function. The three methods used to reduce prostate mass (castration, finasteride, Pbsn4cre/+; R26RDta/+) changed voiding function from baseline but in a nonuniform manner. Castration feminized some aspects of male urinary physiology (making them more like intact female) while exogenous testosterone masculinized some aspects of female urinary physiology (making them more like intact male). Our results provide evidence that circulating testosterone is responsible in part for baseline sex differences in C57BL/6J mouse voiding function while prostate lobe mass in young, healthy adult mice has a lesser influence.

physiology↗