Purpose: The prevalence of lower urinary tract symptoms (LUTS), characterized by problems regarding storage and/or voiding of urine, is known to significantly increase with age. Effective communication between the lower urinary tract and the central nervous system (CNS) is essential for the optimal function of this system, and heavily relies on the efficient interaction between the bladder urothelium and the afferent nerve fibers situated in close proximity to the urothelium within the lamina propria. Methods: We aimed to quantify aging-related differences in the expression of calcitonin gene-related peptide (CGRP, an established marker for sensory nerve fibers) in the trigonal mucosal layers of young (3–4 months) and aged (25–30 months) rats. We evaluated trigonal tissue from 3 animals per age group. Tissue was serially sectioned at 10 μm and stained for CGRP. Images were taken along the full length of the tissue. For each image we computed the total CGRP-positive area (μm2) and the median value for each animal was used for further analysis. Results: Upon statistical analysis the aged rats show a significantly lower CGRP-positive area compared to young rats (P=0.0049). These results indicate that aging has a negative effect on the area of CGRP-positive signal in the trigone. Conclusions The structural and functional integrity of the sensory web in the trigonum of rats is negatively affected by the aging process, potentially leading to impaired communication between the bladder urothelium the CNS. Consequently, these perturbations in the sensory system may contribute to the pathogenesis or exacerbation LUTS.

Purpose: The pathophysiology of nocturia and nocturnal polyuria (NP), conditions that become more prevalent with aging, may in part be explained by changes in hormones involved in water homeostasis. The purpose of this study was to analyze the impact of aging on urinary natriuretic peptides in nocturia and NP. Methods: Patients aged ≥18 years completed 24-hour bladder diaries for assessment of nocturia and NP. They were divided into subgroups of ≥65 years old and <65 years old. Urine samples were collected and analyzed for natriuretic peptide (NT-proANP, NT-proBNP, and NT-proCNP) levels. Peptide levels were compared between patients with and without nocturia/NP and within age subgroups; correlation to the NP index (NPi) was determined. Results: Compared to patients without nocturia (N=15), patients with nocturia (N=36) had higher median levels of urinary NT-proANP (15.8 pmol/mmol Cr vs. 10.9 pmol/mmol Cr, P=0.016) and NT-proBNP (6.3 pmol/mmol Cr vs. 4.5 pmol/mmol Cr, P=0.021), but showed no differences in NT-proCNP (2.4 pmol/mmol Cr vs. 2.5 pmol/mmol Cr, P=0.967). Patients ≥65 years old with nocturia had higher NT-proANP (29.8 pmol/mmol Cr vs. 11.0 pmol/mmol Cr, P<0.001) and NT-proBNP (9.6 pmol/mmol Cr vs. 5.0 pmol/mmol Cr, P<0.001) than patients <65 years old. Additionally, patients with NP (N=30) showed higher urinary NT-proANP (19.6 pmol/mmol Cr vs. 10.5 pmol/mmol Cr, P<0.001) and NT-proBNP (6.7 pmol/mmol Cr vs. 4.7 pmol/mmol Cr, P=0.020) compared to patients without NP (N=21). NP patients ≥65 years had higher NT-proANP (29.8 pmol/mmol Cr vs. 12.5 pmol/mmol Cr, P<0.001) and NT-proBNP (9.6 pmol/mmol Cr vs. 4.4 pmol/mmol Cr, P=0.004) than patients <65 years old. NPi positively correlated with urinary NT-proANP (RS=0.417, P=0.002) and NT-proBNP (RS=0.303, P=0.031), but not with NT-proCNP (RS=-0.094, P=0.510). Conclusions Since urinary NT-proANP and NT-proBNP were greater in aged patients with nocturia and NP, natriuretic peptides may contribute to the pathophysiology of these conditions and further research should aim to explore them as targets for management.

Purpose: Lower urinary tract symptoms are known to significantly increase with age, negatively impacting quality of life and self-reliance. The urothelium fulfills crucial tasks, serving as a barrier protecting the underlying bladder tissue from the harsh chemical composition of urine, and exhibits signaling properties via the release of mediators within the bladder wall that affect bladder functioning. Aging is associated with detrimental changes in cellular health, in part by increasing oxidative stress in the bladder mucosa, and more specifically the urothelium. This, in turn, may impact urothelial mitochondrial health and bioenergetics. Methods: We collected mucosal tissue samples from both young (3–4 months old) and aged (25–30 months old) rats. Tissue was evaluated for p21-Arc, nitrotyrosine, and cytochrome C expression by western immunoblotting. Urothelial cells were cultured for single-cell imaging to analyze basal levels of reactive oxygen species and the mitochondrial membrane potential. Mitochondrial bioenergetics and cellular respiration were investigated by the Seahorse assay, and measurements of adenosine triphosphate release were made using the luciferin-luciferase assay. Results: Aging was associated with a significant increase in biomarkers of cellular senescence, oxidative stress, and basal levels of reactive oxygen species. The mitochondrial membrane potential was significantly lower in urothelial cell cultures from aged animals, and cultures from aged animals showed a significant decrease in mitochondrial bioenergetics. Conclusions Aging-related increases in oxidative stress and excessive reactive oxygen species may be contributing factors underlying lower urinary tract symptoms in older adults. The mechanisms outlined in this study could be utilized to identify novel pharmaceutical targets to improve aging-associated bladder dysfunction.

Purpose: To investigate urothelial cell proliferation, cytoskeleton, inflammation, and barrier function protein expressions in patients with interstitial cystitis/bladder pain syndrome (IC/BPS) after intravesical platelet-rich plasma (PRP) injections Methods: A total of 19 patients with IC/BPS underwent 4 monthly intravesical PRP injections. Bladder biopsies were taken at the first and fourth PRP treatment. The bladder specimens were analyzed using the Western blot and immunochemical staining for progenitor cell markers for sonic hedgehog (Shh), CD34, and cytoskeleton proteins cytokeratin 5 (CK5), CK14, CK20; barrier function markers for zonula occludens-1 (ZO-1), E-cadherin, and intercellular adhesive molecule-1, tryptase and transforming growth factor-β (TGF-β). Global response assessment (GRA) was used to evaluate treatment outcomes. Results: The mean age of patients was 55.6 years. After PRP injections, the functional bladder capacity and maximum flow rate increased, and the visual analogue scale (VAS) of pain, interstitial cystitis (IC) symptom index, IC problem index, O’Leary-Sant symptom score, and GRA improved in all patients. Urothelium Shh, CK5, ZO-1, E-cadherin, and TGF-β expressions increased significantly after repeated PRP injections. By subgrouping, according to PRP treatment outcomes, significant increases in Shh, E-cadherin, and ZO-1 expressions were noted only in patients with GRA ≥1 or improved VAS, but not in patients with GRA=0 and no improvement in VAS. Conclusions The level of urothelial barrier function protein and cell proliferation protein expression in the patients with IC/BPS was increased after repeat intravesical PRP injections. Intravesical repeat PRP injections may have potential to improve urothelial health and result in symptoms improvement in the patients with IC/BPS.

Purpose: To conduct a systematic review of preclinical and clinical peer-reviewed evidence linking alterations in oxidative stress biomarkers or outcome measures that were also prevalent in specific age-related lower urinary tract (LUT) disorders. Methods: PubMed, Scopus, CINAHL, and Embase were searched for peer-reviewed studies published between January 2000 and March 2021. Animal and human studies that reported on the impact of oxidative stress in age-related LUT disorders through structural or functional changes in the LUT and changes in biomarkers were included. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol was followed. Results: Of 882 articles identified, 21 studies (13 animal; 8 human) met inclusion criteria. Across LUT disorders, common structural changes were increased bladder and prostate weights, ischemic damage, nerve damage and detrusor muscle hypertrophy; common functional changes included decreased bladder contraction, increased bladder sensation and excitability, decreased perfusion, and increased inflammation. The disorders were associated with increased levels of biomarkers of oxidative stress that provided evidence of either molecular damage, protective mechanisms against oxidative stress, neural changes, or inflammation. In all cases, the effect on biomarkers and enzymes was greater in aged groups compared to younger groups. Conclusions Increased oxidative stress, often associated with mitochondrial dysfunction, plays a significant role in the pathogenesis of age-related LUT disorders and may explain their increasing prevalence. This systematic review identifies potential markers of disease progression and treatment opportunities; further research is warranted to evaluate these markers and the mechanisms by which these changes may lead to age-related LUT disorders.

Purpose: Substantive evidence supports a role of chronic stress in the development, maintenance, and even enhancement of functional bladder disorders such as interstitial cystitis/bladder pain syndrome (IC/BPS). Increased urinary frequency and bladder hyperalgesia have been reported in rodents exposed to a chronic stress paradigm. Here, we utilized a water avoidance stress (WAS) model in rodents to investigate the effect of chronic stress on vascular perfusion and angiogenesis. Methods: Female Wistar-Kyoto rats were exposed to WAS for 10 consecutive days. Bladder neck tissues were analyzed by western immunoblot for vascular endothelial growth factor (VEGF) and nerve growth factor precursor (proNGF). Vascular perfusion was assessed by fluorescent microangiography followed by Hypoxyprobe testing to identify regions of tissue hypoxia. Results: The expression of VEGF and proNGF in the bladder neck mucosa was significantly higher in the WAS rats than in the controls. There was a trend toward increased vascular perfusion, but without a statistically significant difference from the control group. The WAS rats displayed a 1.6-fold increase in perfusion. Additionally, a greater abundance of vessels was observed in the WAS rats, most notably in the microvasculature. Conclusions These findings show that chronic psychological stress induces factors that can lead to increased microvasculature formation, especially around the bladder neck, the region that contains most nociceptive bladder afferents. These findings may indicate a link between angiogenesis and other inflammatory factors that contribute to structural changes and pain in IC/BPS.

Purpose: Low nocturnal urine production (NUP) may be sufficient to rule out global polyuria (GP) in men. This study determines the sensitivity of indices for nocturnal polyuria (NP), defined as nocturnal polyuria index (NPi; nocturnal urine volume/24-hour urine volume) ≥0.33 or NUP ≥90 mL/hr, for detecting GP in women. Methods: Data were analyzed from 2 prospective protocols involving subjects recruited from a urology ambulatory care unit and a continence clinic. Women ≥18 years with nocturia were included if they met either of 2 common criteria for GP: (1) ≥40 mL/kg/24 hr or (2) ≥3,000 mL/24 hr. Results: Thirty-one women were included (NPi, 28.6 [21.3–40.7]; NUP, 100.8 [68.3–135.8] mL/hr). At the ≥40 mL/kg/24-hr cutoff, 40% and 63% of women reporting ≥1 nocturnal void(s) (n=30) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. Additionally, 53% and 71% of subjects reporting ≥2 nocturnal voids (n=17) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. At the ≥3,000 mL/24-hr cutoff, 38% and 69% of women reporting ≥1 nocturnal void(s) (n=13) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively, and 63% and 88% of subjects reporting ≥2 nocturnal voids (n=8) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. By extension, 37%–62% of women with nocturia and GP did not have NP by NPi ≥0.33 criteria, and 12%–37% did not have NP by NUP ≥90 mL/hr criteria. Conclusions Indices of excess nighttime urination do not reliably predict GP in women. A full-length voiding diary may be particularly important in the evaluation of women with nocturia. Nocturia in women merits further consideration as a distinct entity.