The urothelium: a multi-faceted barrier against a harsh environment

Microplastic pollution: a review of specific blood-tissue barrier breaches and health effects

Microplastic (1 μm - 5 mm) and nanoplastic (<1 μm) pollution is a heightening global challenge affecting the environment and the health of living creatures within. As primary precursors for plastic manufacturing, microplastics predominantly get into the environment through plastic product degradation and integrate into water, food chain and consumer products leading to potential health consequences. The mammalian system is equipped with several blood-tissue barriers with exclusive tight junctions that selectively regulate material transfer and protect vulnerable and functionally important organs. Nonetheless, emerging evidence indicates microplastics interact, traverse and compromise the integrity of these complex barriers. This review summarises the known and potential impact of microplastics on human health, focusing on specific organ barrier breaches. Evidence of microplastic traversal and deposition in distal mammalian organs are discussed. We further highlight current challenges facing both researchers and clinicians and provide an outlook for expanding our understanding of the impact of microplastic on health.

Poly(L-lactic acid)/gelatin microfiber membrane loaded with mitomycin C promoting bladder defect repair by anti-fibrosis and antibacterial action

When the bladder is affected by factors such as tumors, tuberculosis, or trauma, its normal structure and function can be severely damaged. At this point, bladder replacement or enlargement surgery may become necessary to restore its structure and improve the patient's quality of life. Traditional bladder reconstruction surgery, specifically ileum augmentation cystoplasty, involves a complex surgical process, along with relatively large operative wounds and possible intestinal obstruction complications. There is also an urgent need for suitable bladder replacement materials. Over the past decade, synthetic bladder scaffolds have emerged as alternatives; however, most fail to simultaneously address the issues of postoperative fibrosis and bacterial infection. To overcome these challenges, we developed an electrospun poly(L-lactic acid)/gelatin (PLLA/GEL) microfiber membrane loaded with mitomycin C (MMC). By optimizing the PLLA/GEL ratio (7 : 3), the membrane exhibited both good rigidity and excellent elasticity. The MMC-loaded fibers demonstrated sustained drug release, effectively inhibiting E. coli and S. aureus in vitro. In rat partial cystectomy models, the PLLA/GEL/MMC group showed a reduction in collagen III deposition through inhibition of the TGF-β/Smad2 pathway, as well as enhanced urothelium regeneration and promotion of angiogenesis. Notably, the membrane maintained cell viability for both urothelial cells and smooth muscle cells over 7 days, confirming its biocompatibility. These findings highlight the promising potential of the PLLA/GEL/MMC microfiber membrane not only as a material for bladder tissue engineering but also as a tool for therapeutic intervention that addresses multiple facets of bladder healing and regeneration.

Strategies of Bladder Reconstruction after Partial or Radical Cystectomy for Bladder Cancer

The standard strategy is to reconstruct bladder by use of bowel segments as material in bladder cancer with radical cystectomy clinically. Both natural derived and non natural derived materials are investigated in bladder reconstruction. Studies on mechanical bladder, bladder transplantation and bladder xenotransplantation are currently limited although heart and kidney transplantation or xenotransplantation are successful to a certain extent, and bone prostheses are applied in clinical contexts. Earlier limited number of studies associated with bladder xenograft from animals to humans were not particular promising in results. Although there have been investigations on pig to human cardiac xenotransplantation with CRISPR Cas9 gene editing, the CRISPR Cas technique is not yet widely researched in porcine bladder related gene editing for the potential of human bladder replacement for bladder cancer. The advancement of technologies such as gene editing, bioprinting and induced pluripotent stem cells allow further research into partial or whole bladder replacement strategies. Porcine bladder is suggested as a potential source material for bladder reconstruction due to its alikeness to human bladder. Challenges that exist with all these approaches need to be overcome. This paper aims to review gene editing technology such as the CRISPR Cas systems as tools in bladder reconstruction, bladder xenotransplantation and hybrid bladder with technologies of induced pluripotent stem cells and genome editing, bioprinting for bladder replacement for bladder reconstruction and to restore normal bladder control function after cystectomy for bladder cancer.

Potential applications and mechanisms of natural products in mucosal-related diseases

The mucosal barrier serves as a crucial defense against external pathogens and allergens, being widely distributed across the respiratory, gastrointestinal, urogenital tracts, and oral cavity. Its disruption can lead to various diseases, including inflammatory bowel disease, asthma, urinary tract infections, and oral inflammation. Current mainstream treatments for mucosa-associated diseases primarily involve glucocorticoids and immunosuppressants, but their long-term use may cause adverse effects. Therefore, the development of safer and more effective therapeutic strategies has become a focus of research. Natural products, with their multi-target and multi-system regulatory advantages, offer a promising avenue for the treatment of mucosal diseases. This review summarizes the potential applications of natural products in diseases of mucosal barrier dysfunction through mechanisms such as immune modulation, inflammation inhibition, tight junction protein restoration, and gut microbiota regulation, with the aim of providing insights for the exploration of novel therapeutic strategies.

Phases of tight junction barrier disruption during transurothelial migration of invasive urothelial cancer cells

Bladder cancer is characterised by its multifocal nature and a high recurrence, yet the underlying mechanisms of these phenomena remain only partially understood. In the present study, we aimed to investigate transurothelial invasion of urothelial cancer cells as a potential mechanism for dissemination of bladder cancer and to identify the key molecules involved in urothelial barrier disruption. Using confocal and electron microscopy, we were able to show that within a 24-hour timeframe muscle-invasive urothelial cancer cells T24 adhere to the partially differentiated normal urothelial in vitro model and initially cause localised disruption of the tight junctions between urothelial cells. Subsequently, urothelial cells separate and individual T24 cells migrate paracellularly through the urothelium. qPCR analysis identified fibroblast activation protein (FAP)/seprase as the candidate most likely to be involved in urothelial barrier disruption. In addition, treatment of T24 cells with Pefabloc resulted in the inhibition of T24 cell invasion. Our results contribute to the understanding of the mechanisms underlying transurothelial invasion of urothelial cancer cells. Among the molecules tested, FAP/sepraseis likely involved in cancer cell-induced disruption of the urothelial barrier, suggesting its potential as a therapeutic target to prevent progression and recurrence of bladder cancer.

The Role of Innate Immunity in Healthy Aging Through Antimicrobial Peptides

In a super-aging society, the increase in the elderly population is closely tied to a rise in infectious diseases due to factors such as weakened immune systems and decreased vaccine efficacy in older adults. Various opportunistic pathogens commonly encountered in everyday life can cause infections and diseases when an individual's immune defence is weakened due to aging. These factors underscore the importance of preventive measures against pathogenic infections and the aging of immune systems in the elderly. The immune response acts as the defence mechanism against foreign substances, including pathogens and abnormal cells. Specifically, the innate immune response is the body's first line of defence, offering a rapid and nonspecific response to pathogens. Advances in the study of innate immunity's regulatory functions in both immune and non-immune cells have broadened our understanding of innate immune responses' impact on health. This includes a focus on immune effectors like antimicrobial peptides (AMPs) and their potential implications for health and longevity. This review summarises the common principles and evolutionary adaptations of innate immunity via AMPs, in mammals and invertebrates. Especially, this review discusses the conserved mechanisms regulating AMP production and the role of AMPs in modulating aging and diseases from invertebrate to human. Therefore, it highlights the potential role of innate immunity in addressing aging through AMPs.

Pathophysiology and potential treatment modalities in women with recurrent urinary tract infection

Urinary tract infection (UTI) of the urinary bladder is a common bacterial infection that predominantly affects women, with many experiencing recurrent episodes. Recurrent UTIs (rUTIs) are associated with significant physical, psychological, and social difficulties. Further, they are closely related to lower urinary tract dysfunction (LUTD). LUTD affects bladder function and structure, thereby contributing to urinary urgency, frequency, and incontinence, which, in turn, increases the risk of recurrent infections due to impaired urothelial defense mechanisms. The current study explored the pathophysiology of LUTD in women with rUTIs. Potential treatments for rUTIs include long-term prophylactic antibiotics, probiotics, D-mannose, vaccines, small molecule inhibitors, and stem cell therapy. Moreover, it evaluated the use of platelet-rich plasma (PRP) therapy as a treatment modality for LUTD. PRP has regenerative and anti-inflammatory properties. Hence, it can be a promising option for enhancing urothelial barrier integrity and reducing infection recurrence. Repeated intravesical PRP injections are effective in improving bladder symptoms and decreasing UTI recurrences by enhancing the proliferative ability of the urothelium in patients with rUTIs. Further, this review examined the potential predictors of successful PRP treatment outcomes such as cytokine and urothelial biomarker levels, which provided insights into patient selection and individualized treatment strategies. Identifying the predictive biomarkers of treatment responsiveness is essential for optimizing PRP therapy. Hence, to improve the clinical outcomes and quality of life of patients with rUTIs, future research should focus on refining the use of PRP, exploring combination therapies, and validating biomarkers.

Perspective on the use of optics in bladder cancer detection and diagnosis

Significance

Bladder cancer (BC) diagnosis, management, and outcomes depend on the accurate detection of tumors via optical technologies. Accordingly, understanding the benefits and limitations of these technologies permits improvements in patient care and identifies areas for future research.

Aim

We outline the current process of BC detection and diagnosis, explore the current role of optical technologies, and discuss the opportunities and challenges they present in this field.

Approach

The current diagnostic pathway of BC, the use of optical technologies, and their shortcomings in this process are reviewed. From there, opportunities and challenges of optics in BC detection and diagnosis are discussed.

Results

BC management is expensive due to the limitations of white light cystoscopy, the requirement for histopathological confirmation, and the need for long-term surveillance. Alternative non-optical methods lack accuracy, and available optical techniques focus only on cancer detection. Alternatives to histopathology need to provide accurate real-time results to be effective. Optical advancements offer potential benefits; however, challenges include cost-effectiveness, device complexity, required training, and tumor heterogeneity.

Conclusions

Optical techniques could accelerate BC diagnosis, reduce costs, and enable alternative treatments. However, overcoming technical and practical challenges is essential for their successful integration.

PKD1 mutation perturbs morphogenesis in tubular epithelial organoids derived from human pluripotent stem cells

Autosomal dominant polycystic kidney disease (ADPKD) is the most common renal genetic disease, with most patients carrying mutations in PKD1. The main feature is the formation of bilateral renal cysts, leading to end stage renal failure in a significant proportion of those affected. Despite recent advances made in understanding ADPKD, there are currently no effective curative therapies. The emergence of human induced pluripotent stem cell (hiPSC)-derived kidney disease models has led to renewed hope that more physiological systems will allow for the development of novel treatments. hiPSC-derived organoid models have been used to recapitulate ADPKD, however they present numerous limitations which remain to be addressed. In the present study, we report an efficient method for generating organoids containing a network of polarised and ciliated epithelial tubules. PKD1 null (PKD1-/-) organoids spontaneously develop dilated tubules, recapitulating early ADPKD cystogenesis. Furthermore, PKD1-/- tubules present primary cilia defects when dilated. Our model could therefore serve as a valuable tool to study early ADPKD cystogenesis and to develop novel therapies.

A bladder blueprint to build better models for understanding homeostasis and disease

The bladder is a complex organ that can be affected by various pathologies, such as cancer or infection. It has a specific tissue structure composed of many different cell types and layers, including urothelial and endothelial cells but also a muscle layer controlling stretch and contraction to void urine. The bladder has constitutive and induced immune responses to infection or damage and harbours a microbiome. Each of these features can be influenced by factors including age and biological sex, which makes modelling homeostasis and disease in the bladder complex and challenging. To model diseases that affect the bladder, mouse models are an invaluable tool to understand the bladder in situ. However, stark differences exist between mice and humans, and so mouse models of human disease have limitations. Thus, models that more closely approximate human physiology would be expected to contribute to improved understanding of bladder biology. As technology advances, improvements in model development and creation of 3D bladder structures are enabling scientists to recapitulate essential aspects of human bladder physiology to gain increased understanding of bladder homeostasis and diseases.

Ochoa S, Xicohtencatl-Cortes J. Pathogenesis and Immunomodulation of Urinary Tract Infections Caused by Uropathogenic Escherichia coli

Urinary tract infections (UTIs) are a leading cause of illness in children and adults of all ages, with uropathogenic Escherichia coli (UPEC) being the primary agent responsible. During colonization and subsequent infection of the urinary tract (UT), UPEC requires the expression of genes associated with virulence, such as those that encode the fimbrial adhesins FimH, PapG, and CsgA, as well as the presence of the TosA protein and the flagellar appendages of the bacteria. However, for colonization and infection to be successful, UPEC must overcome the host's immunological barriers, such as physical barriers, expressed peptides and proteins, and immune cells found in the UT. In this context, the UT functions as an integral system where these factors act to prevent the colonization of uropathogens. Significant genetic diversity exists among UPEC strains, and the clonal complex ST131 represents one of the key lineages. This lineage has a high content of virulence genes, multiple mechanisms of antibiotic resistance, and a high frequency of extended-spectrum β-lactamases (ESBLs). New knowledge regarding protein structures known as adhesins and their role in the infection process can help identify therapeutic targets and aid in the design of vaccines. These vaccines could be based on the development of chimeric fusion proteins (FimH + CsgA + PapG), which may significantly reduce the incidence of UTIs in pediatric and adult patients.

Analysis of human urinary extracellular vesicles reveals disordered renal metabolism in myotonic dystrophy type 1

Chronic kidney disease (CKD) and the genetic disorder myotonic dystrophy type 1 (DM1) each are associated with progressive muscle wasting, whole-body insulin resistance, and impaired systemic metabolism. However, CKD is undocumented in DM1 and the molecular pathogenesis driving DM1 is unknown to involve the kidney. Here we use urinary extracellular vesicles (EVs), RNA sequencing, droplet digital PCR, and predictive modeling to identify downregulation of metabolism transcripts Phosphoenolpyruvate carboxykinase-1, 4-Hydroxyphenylpyruvate dioxygenase, Dihydropyrimidinase, Glutathione S-transferase alpha-1, Aminoacylase-1, and Electron transfer flavoprotein B in DM1. Expression of these genes localizes to the kidney, especially the proximal tubule, and correlates with muscle strength and function. In DM1 autopsy kidney tissue, characteristic ribonuclear inclusions are evident throughout the nephron. We show that urinary organic acids and acylglycines are elevated in DM1, and correspond to enzyme deficits of downregulated genes. Our study identifies a previously unrecognized site of DM1 molecular pathogenesis and highlights the potential of urinary EVs as biomarkers of renal and metabolic disturbance in these individuals.

The fundamentals of WNT10A

Human wingless-type MMTV integration site family member 10A (WNT10A) is a secreted glycoprotein that is involved in signaling pathways essential to ectodermal organogenesis and tissue regeneration. WNT10A was first linked to human disorders in 2006, demonstrating a WNT10a variant to be associated with cleft lip with/without cleft palate. Numerous publications have since then identified the importance of WNT10A in the development of ectodermal appendages and beyond. In this review, we provide information on the structure of the WNT10A gene and protein, summarize its expression patterns in different animal models and in human, and describe the identified roles in tissue and organ development and repair in the different animal model organisms. We then correlate such identified functions and working mechanisms to the pathophysiology of a spectrum of human diseases and disorders that result from germline loss-of-function mutations in WNT10A, including ectodermal dysplasia (ED) syndromes Odonto-oncho-dermal dysplasia (OODD), Schöpf-Schulz-Passarge syndrome (SSPS), and selective tooth agenesis, as well as pathological conditions like fibrosis and carcinogenesis that can be correlated with increased WNT10A activity (Section 5).

Advancements in the management of overactive bladder in women using nano-botulinum toxin type A: A narrative review

Intravesical injections of botulinum toxin type A (BTX-A) are effective for treating refractory overactive bladder (OAB) in women. However, the adverse effects linked to the injections, such as hematuria, pain, and infection, and need for repeated injections can lower patient compliance and make the treatment inconvenient. Hence, urologists are actively pursuing less invasive and more convenient methods for the intravesical delivery of BTX-A. Advances in nanotechnology have facilitated noninvasive intravesical drug delivery. Currently, liposomes, hydrogels, nanoparticles, and many other forms of carriers can be used to enhance bladder wall permeability. This facilitates the entry of BTX-A into the bladder wall, allowing it to exert its effects. In this review, the feasibility and efficacy of liposomes, thermosensitive hydrogels, and hyaluronic acid-phosphatidylethanolamine for the treatment of OAB in women are discussed along with recent animal experiments on the use of nanotechnology-delivered BTX-A for the treatment of OAB in female rat models. Although the clinical efficacy of nanocarrier-encapsulated BTX-A for the treatment of OAB in women has not yet matched that of direct urethral muscle injection of BTX-A, improvements in certain symptoms indicate the potential of bladder instillation of nanocarrier-encapsulated BTX-A for future clinical applications. Consequently, further research on nanomaterials is warranted to advance the development of nanocarriers for the noninvasive delivery of BTX-A in the bladder.

Urinary bladder diverticula: imaging features and complications

Urinary bladder diverticula are common and are frequently incidentally discovered. Many downstream complications can occur due to urinary stasis, such as bladder diverticular stones, infection, and malignancy. Understanding the physiology of bladder diverticula and potential pitfalls and mimics is critical to an accurate description of bladder diverticula and early detection of potential downstream complications. This pictorial review will first review the normal bladder histology and function, bladder diverticular types, and typical imaging features. The paper will then draw attention to technical pitfalls and potential mimics. Finally, we will review the downstream complications, including stones, infection, malignancy, and BCG-related changes.

Development of a unique crosslinked glycosaminoglycan for soft tissue repair: Treatment of interstitial cystitis/bladder pain syndrome

Chemical modification of naturally derived glycosaminoglycans (GAGs) expands their potential utility for applications in soft tissue repair and regenerative medicine. Here we report the preparation of a novel crosslinked chondroitin sulfate (~200 to 2000 kilodaltons) that is both soluble in aqueous solution and microfilterable. We refer to these materials as "SuperGAGs." One can further conjugate these materials with diverse capture agents to further modify polymer properties and add new capabilities. A representative material (GLX-100) demonstrated durable restoration of bladder impermeability in a gold standard animal model of Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). Histologic examination of the animal bladders treated with a GLX-100 SuperGAG conjugated to biotin as a reporter demonstrated that the residence time of GLX-100 is superior to chondroitin sulfate (a product that is currently used for clinical treatment of patients with IC/BPS). As expected, this novel crosslinked GAG biopolymer was restricted to the luminal surface of the bladder wall. In this communication we describe a simple and versatile synthesis of a crosslinked glycosaminoglycan (GAG) biopolymer for soft tissue repair. Chondroitin sulfate (~12 kD) was crosslinked to form a water soluble and microfilterable polymer with approximately 200 to 2000 kD molecular weight. The synthesis presented here allows for control of molecular weight while avoiding formation of an extended block gel. Moreover, the procedure enables further chemical modification of the SuperGAG through the selection of a capture agent. A set of agents have been used, demonstrating the preparation of a family of SuperGAGs with diverse capabilities. We can optimize polymer properties, adjust adherence to various tissues, add reporters, and engage the biochemistry of surrounding tissues with peptides and other bioactives.

Irx1 mechanisms for oral epithelial basal stem cell plasticity during reepithelialization after injury

The oral mucosa undergoes daily insults, and stem cells in the epithelial basal cell layer regenerate gingiva tissue to maintain oral health. The Iroquois Homeobox 1 (IRX1) protein is expressed in the stem cell niches in human/mouse oral epithelium and mesenchyme under homeostasis. We found that Irx1+/- heterozygous (Het) mice have delayed wound closure, delayed morphological changes of regenerated epithelium, and defective keratinocyte proliferation and differentiation during wound healing. RNA-Seq analyses between WT and Irx1+/- mice at 3 days postinjury (dpi) found impaired epithelial migration and decreased keratinocyte-related genes upon injury. IRX1-expressing cells are found in the gingival epithelial basal cell layer, a stem cell niche for gingival maintenance. IRX1-expressing cells are also found in cell niches in the underlying stroma. IRX1 activates SOX9 in the transient amplifying layer to increase cell proliferation, and EGF signaling is activated to induce cell migration. Krt14CreERT lineage tracing experiments reveal defects in the stratification of the Irx1+/- HET mouse oral epithelium. IRX1 is primed at the base of the gingiva in the basal cell layer of the oral epithelium, facilitating rapid and scarless wound healing through activating SOX9 and the EGF signaling pathway.

IFRD1 is required for maintenance of bladder epithelial homeostasis

The maintenance of homeostasis and rapid regeneration of the urothelium following stress are critical for bladder function. Here, we identify a key role for IFRD1 in maintaining urothelial homeostasis in a mouse model. We demonstrate that the murine bladder expresses IFRD1 at homeostasis, particularly in the urothelium, and its loss alters the global transcriptome with significant accumulation of endolysosomes and dysregulated uroplakin expression pattern. We show that IFRD1 interacts with mRNA-translation-regulating factors in human urothelial cells. Loss of Ifrd1 leads to disrupted proteostasis, enhanced endoplasmic reticulum (ER stress) with activation of the PERK arm of the unfolded protein response pathway, and increased oxidative stress. Ifrd1-deficient bladders exhibit urothelial cell apoptosis/exfoliation, enhanced basal cell proliferation, reduced differentiation into superficial cells, increased urothelial permeability, and aberrant voiding behavior. These findings highlight a crucial role for IFRD1 in urothelial homeostasis, suggesting its potential as a therapeutic target for bladder dysfunction.

Distinctive roles of aquaporins and novel therapeutic opportunities against cancer

Aquaporins (AQPs) are integral membrane proteins responsible for facilitating the transmembrane transport of water and small solutes. Their involvement in diverse physiological functions extends to pathological conditions, including cancer, positioning them as promising targets for anticancer therapy. Tumor cells, particularly those with high metastatic potential, exhibit elevated AQP expression, reinforcing their critical role in tumor biology. Emerging evidence highlights AQPs' involvement in key oncogenic processes such as cell migration, proliferation, and tumor-associated edema, suggesting their potential as novel therapeutic targets. Despite this, the development of selective and potent AQP inhibitors has proven challenging. Efforts to produce small-molecule AQP inhibitors have largely been unsuccessful. However, recent advancements include monoclonal human IgG antibodies targeting extracellular domains of aquaporin-4, offering new therapeutic strategies, particularly in glioblastoma, where AQP-4 is overexpressed. However, recent advancements include monoclonal human IgG antibodies targeting extracellular domains of aquaporin-4, offering new therapeutic strategies, particularly in glioblastoma, where AQP-4 is over expressed. These antibodies hold promise for selectively targeting and eradicating AQP-4-expressing cells in malignant brain tumors. This review discusses the critical role AQPs play in cancer, including their contributions to tumor cell proliferation, migration, angiogenesis, and edema formation. Additionally, we explore innovative therapeutic approaches, such as antibody-based interventions, and outline potential future research directions in AQP-targeted cancer therapies.

Walthard Cell Nests/Transitional Cell Metaplasia in Distal Fallopian Tubes and Pelvic Peritoneum Derived From Reserve Cells

Transitional cell metaplasia (TCM) resembling benign urothelium is commonly seen around the distal fallopian tube and/or neighboring mesothelial surface; however, its histogenesis remains largely unknown. We observed the emergence of a cytokeratin (CK) 17-positive reserve cell layer in early TCM foci beneath the tubal epithelium, leading us to hypothesize that TCM could be derived from reserve cells. To elucidate the histogenetic process of TCM, we analyzed the histomorphologic features and immunoprofiles for CK17, CK5/6, p63, GATA-3, estrogen receptor (ER), and androgen receptor (AR) in TCM foci arising in the tubal epithelium (31 foci) and pelvic mesothelium (35 foci). Overall, the histologic features and immunoprofiles of TCM in the tubal epithelium and pelvic mesothelium were similar, but distinct differences appeared during TCM development. A single-layered CK17-expressing reserve cells became apparent beneath the tubal epithelium, and the CK17 expression disappeared as these cells multiplied. In contrast, a short segment of normal mesothelium next to the tubo-peritoneal junction expressed CK17 even before the emergence of a single-layered reserve cells beneath the mesothelium, suggesting a potential reserve/stem cell function within the mesothelium itself. Then, the single-layered cells in both areas multiplied and differentiated to display urothelial characteristics, including nuclear grooves and clear cytoplasm. Strong CK5/6, p63, and GATA-3 expression appeared in the single-layered reserve cell stage and was maintained thereafter to the fully differentiated TCM. AR was expressed in both normal tubal epithelium and pelvic mesothelium, and the intensity of AR and ER were reciprocal during the entire histogenetic process of TCM in most reserve cell-derived populations (98.5%), AR expression being significantly stronger than ER. The histogenesis of TCM was initiated from the emergence of reserve cells beneath the tubal epithelium and pelvic mesothelium, which then multiplied and differentiated into urothelium. AR might have an important role during the histogenesis of TCM.

Peripheral Mechanisms Underlying Bacillus Calmette-Guerin-Induced Lower Urinary Tract Symptoms (LUTS)

Non-muscle invasive bladder cancer (NMIBC) accounts for approximately 70-75% of all bladder cancer cases. The standard treatment for high-risk NMIBC involves transurethral tumour resection followed by intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. While BCG immunotherapy is both safe and effective, it frequently leads to the development of lower urinary tract symptoms (LUTS) such as urinary urgency, frequency, dysuria, and pelvic discomfort. These symptoms can significantly diminish patients' quality of life and may result in the discontinuation of BCG treatment, adversely affecting oncological outcomes. Despite the considerable clinical impact of BCG-induced LUTS, the underlying mechanisms remain unclear, hindering the implementation or development of effective treatments. This review provides novel insights into the potential mechanisms underlying BCG-induced LUTS, focusing on the integrated roles of afferent and efferent nerves in both normal and pathological bladder sensation and function. Specifically, this review examines how the body's response to BCG-through the development of inflammation, increased urothelial permeability, and altered urothelial signalling-might contribute to LUTS development. Drawing from known mechanisms in other common urological disorders and data from successful clinical trials involving NMIBC patients, this review summarises evidence supporting the likely changes in both sensory nerve signalling and bladder muscle function in the development of BCG-induced LUTS. However, further research is required to understand the intricate mechanisms underlying the development of BCG-induced LUTS and identify why some patients are more likely to experience BCG intolerance. Addressing these knowledge gaps could have profound implications for patients' quality of life, treatment adherence, and overall outcomes in NMIBC care.

Bacterial-host adhesion dominated by collagen subtypes remodelled by osmotic pressure

Environmental osmolarity plays a crucial role in regulating the functions and behaviors of both host cells and pathogens. However, it remains unclear whether and how environmental osmotic stimuli modulate bacterial‒host interfacial adhesion. Using single-cell force spectroscopy, we revealed that the interfacial adhesion force depended nonlinearly on the osmotic prestimulation of host cells but not bacteria. Quantitatively, the adhesion force increased dramatically from 25.98 nN under isotonic conditions to 112.45 or 93.10 nN after the host cells were treated with the hypotonic or hypertonic solution. There was a strong correlation between the adhesion force and the number of host cells harboring adherent/internalized bacteria. We further revealed that enhanced overexpression levels of collagen XV and II were responsible for the increases in interfacial adhesion under hypotonic and hypertonic conditions, respectively. This work provides new opportunities for developing host-directed antibacterial strategies related to interfacial adhesion from a mechanobiological perspective.

Exploring hypoxia-induced ncRNAs as biomarkers and therapeutic targets in lung cancer

Lung cancer is a deadly disease, causing nearly 20 % of all cancer deaths globally. A key factor in lung cancer's development and resistance to treatment is hypoxia, a condition where tumor cells experience low oxygen levels. In this low-oxygen environment, special molecules called non-coding RNAs (ncRNAs) become critical players. NcRNAs, including lncRNAs, miRNAs, circRNAs, and siRNAs, control how genes function and how cells behave. Some ncRNAs, like HIF1A-AS2 and HOTAIR, are linked to the aggressive spread of lung cancer, making them potential targets for therapy. Others, like certain miRNAs, show promise as early detection tools due to their influence on tumor blood vessel formation and metabolism. This complex interplay between hypoxia and ncRNAs is crucial for understanding lung cancer. For example, circRNAs can control the activity of miRNAs, impacting how tumors respond to low oxygen. Additionally, siRNAs offer a potential strategy to overcome treatment resistance caused by hypoxia. By studying the intricate relationship between hypoxia and ncRNAs, scientists hope to uncover new biomarkers for lung cancer. This knowledge will pave the way for developing more effective and targeted treatments for this devastating disease.

Untethered Microgrippers for Biopsy in the Upper Urinary Tract

Untethered microrobots offer the possibility to perform medical interventions in anatomically complex and small regions in the body. Presently, it is necessary to access the upper urinary tract to diagnose and treat Upper Tract Urothelial Carcinoma (UTUC). Diagnostic and treatment challenges include ensuring adequate tissue sampling, accurately grading the disease, achieving completeness in endoscopic treatment, and consistently delivering medications to targeted sites. This work introduces microgrippers (µ-grippers) that are autonomously triggered by physiological temperature for biopsy in the upper urinary tract. The experiments demonstrated that µ-grippers can be deployed using standard ureteral catheters and maneuvered using an external magnetic field. The μ-grippers successfully biopsied tissue samples from ex vivo pig ureters, indicating that the thin-film bilayer springs' autonomous, physiologically triggered actuation exerts enough force to retrieve urinary tract tissue. The quality of these biopsy samples is sufficient for histopathological examination, including hematoxylin and eosin (H&E) and GATA3 immunohistochemical staining. Beyond biopsy applications, the µ-grippers' small size, wafer-scale fabrication, and multifunctionality suggest their potential for statistical sampling in the urinary tract. Experimental data and clinical reports underscore this potential through statistical simulations that compare the efficacy of µ-grippers with conventional tools, such as ureteroscopic forceps and baskets.

A biodegradable microgrooved and tissue mechanocompatible citrate-based scaffold improves bladder tissue regeneration

Chronic bladder dysfunction due to bladder disease or trauma is detrimental to affected patients as it can lead to increased risk of upper urinary tract dysfunction. Current treatment options include surgical interventions that enlarge the bladder with autologous bowel tissue to alleviate pressure on the upper urinary tract. This highly invasive procedure, termed bladder augmentation enterocystoplasty (BAE), significantly increases the risk of patient morbidity and mortality due to the incompatibility between bowel and bladder tissue. Therefore, patients would significantly benefit from an alternative treatment strategy that can regenerate healthy tissue and restore overall bladder function. Previous research has demonstrated the potential of citrate-based scaffolds co-seeded with bone marrow-derived stem/progenitor cells as an alternative graft for bladder augmentation. Recognizing that contact guidance can potentially influence tissue regeneration, we hypothesized that microtopographically patterned scaffolds would modulate cell responses and improve overall quality of the regenerated bladder tissue. We fabricated microgrooved (MG) scaffolds using the citrate-based biomaterial poly (1,8-octamethylene-citrate-co-octanol) (POCO) and co-seeded them with human bone marrow-derived mesenchymal stromal cells (MSCs) and CD34+ hematopoietic stem/progenitor cells (HSPCs). MG POCO scaffolds supported MSC and HSPC attachment, and MSC alignment within the microgrooves. All scaffolds were characterized and assessed for bladder tissue regeneration in an established nude rat bladder augmentation model. In all cases, normal physiological function was maintained post-augmentation, even without the presence of stem/progenitor cells. Urodynamic testing at 4-weeks post-augmentation for all experimental groups demonstrated that bladder capacity increased and bladder compliance was normal. Histological evaluation of the regenerated tissue revealed that cell-seeded scaffolds restored normal bladder smooth muscle content and resulted in increased revascularization and peripheral nerve regeneration. The presence of microgrooves on the cell-seeded scaffolds increased microvasculature formation by 20 % and urothelial layer thickness by 25 % in the regenerating tissue. Thus, this work demonstrates that microtopography engineering can influence bladder tissue regeneration to improve overall anatomical structure and re-establish bladder physiology.

Device-Assisted Therapy in Non-Muscle-Invasive Bladder Cancer

Intravesical therapy is a critical component in the management of non-muscle-invasive bladder cancer (NMIBC), as it reduces rates of disease recurrence and progression. However, the presence of physiologic barriers in the urothelium reduces the penetration and distribution of intravesical chemotherapy, thereby limiting the therapeutic potential. Much progress to overcome this challenge has been made in the realm of intravesical device-assisted therapy. Novel device-assisted treatments include hyperthermia, the radiofrequency-induced thermochemotherapy effect, electromotive drug administration, and implantable drug delivery systems. Notably, chemotherapy enhanced by these device-assisted systems has shown improved oncologic efficacy relative to standard intravesical chemotherapy and comparable outcomes relative to Bacillus Calmette-Guérin (BCG) therapy in patients with intermediate- or high-risk NMIBC. Recent studies also support the utility of device-assisted therapy as a salvage treatment option in patients with BCG-unresponsive disease. Ongoing randomized controlled trials and prospective investigations will further help clarify indications and long-term safety outcomes of these treatment modalities in NMIBC. Herein, we present a comprehensive review of device-assisted therapies and discuss their clinical utilities for the management of NMIBC in the modern era.

Periderm fate and independence of tooth formation are conserved across osteichthyans

BACKGROUND

Previous studies have reported that periderm (the outer ectodermal layer) in zebrafish partially expands into the mouth and pharyngeal pouches, but does not reach the medial endoderm, where the pharyngeal teeth develop. Instead, periderm-like cells, arising independently from the outer periderm, cover prospective tooth-forming epithelia and are crucial for tooth germ initiation. Here we test the hypothesis that restricted expansion of periderm is a teleost-specific character possibly related to the derived way of early embryonic development. To this end, we performed lineage tracing of the periderm in a non-teleost actinopterygian species possessing pharyngeal teeth, the sterlet sturgeon (Acipenser ruthenus), and a sarcopterygian species lacking pharyngeal teeth, the axolotl (Ambystoma mexicanum).

RESULTS

In sturgeon, a stratified ectoderm is firmly established at the end of gastrulation, with minimally a basal ectodermal layer and a surface layer that can be homologized to a periderm. Periderm expands to a limited extent into the mouth and remains restricted to the distal parts of the pouches. It does not reach the medial pharyngeal endoderm, where pharyngeal teeth are located. Thus, periderm in sturgeon covers prospective odontogenic epithelium in the jaw region (oral teeth) but not in the pharyngeal region. In axolotl, like in sturgeon, periderm expansion in the oropharynx is restricted to the distal parts of the opening pouches. Oral teeth in axolotl develop long before mouth opening and possible expansion of the periderm into the mouth cavity.

CONCLUSIONS

Restricted periderm expansion into the oropharynx appears to be an ancestral feature for osteichthyans, as it is found in sturgeon, zebrafish and axolotl. Periderm behavior does not correlate with presence or absence of oral or pharyngeal teeth, whose induction may depend on 'ectodermalized' endoderm. It is proposed that periderm assists in lumenization of the pouches to create an open gill slit. Comparison of basal and advanced actinopterygians with sarcopterygians (axolotl) shows that different trajectories of embryonic development converge on similar dynamics of the periderm: a restricted expansion into the mouth and prospective gill slits.

Case reports of immune-related cystitis and the antibody combination hypothesis

Immune-related cystitis is a rare condition, and its diagnostic criteria and pathogenesis are not yet fully understood. Here, we report two cases of immune-related cystitis. Both patients were previously diagnosed with lung squamous cell carcinoma and received combined treatment with immune checkpoint inhibitors and chemotherapy, leading to hemorrhagic cystitis. We reviewed the cystoscopic images and pathological features of previous cases and found that autoantibodies against hemidesmosomes may be the cause of immune-related cystitis, proposing the "antibody combination" hypothesis to explain the tissue specificity of the condition.

The multidrug resistance protein 4 is expressed and functionally active in isolated bladder from pig

Multidrug resistance proteins type 4 (MRP4) and 5 (MRP5) play pivotal roles in the transport of cyclic nucleotides in various tissues. However, their specific functions within the lower urinary tract remain relatively unexplored. This study aimed to investigate the effect of pharmacological inhibition of MRPs on cyclic nucleotide signaling in isolated pig bladder. The relaxation responses of the bladder were assessed in the presence of the MRP inhibitor, MK571. The temporal changes in intra- and extracellular levels of cAMP and cGMP in stimulated tissues were determined by mass spectrometry. The gene (ABCC4) and protein (MRP4) expression were also determined. MK571 administration resulted in a modest relaxation effect of approximately 26% in carbachol-precontracted bladders. The relaxation induced by phosphodiesterase inhibitors such as cilostazol, tadalafil, and sildenafil was significantly potentiated in the presence of MK571. In contrast, no significant potentiation was observed in the relaxation induced by substances elevating cAMP levels or stimulators of soluble guanylate cyclase. Following forskolin stimulation, both intracellular and extracellular cAMP concentrations increased by approximately 15.8-fold and 12-fold, respectively. Similarly, stimulation with tadalafil + BAY 41-2272 resulted in roughly 8.2-fold and 3.4-fold increases in intracellular and extracellular cGMP concentrations, respectively. The presence of MK571 reduced only the extracellular levels of cGMP. This study reveals the presence and function of MRP4 transporters within the porcine bladder and paves the way for future research exploring the role of this transporter in both underactive and overactive bladder disorders.NEW & NOTEWORTHY This study investigates the impact of pharmacological inhibition of MRP4 and MRP5 transporters on cyclic nucleotide signaling in isolated pig bladders. MK571 administration led to modest relaxation, with enhanced effects observed in the presence of phosphodiesterase inhibitors. However, substances elevating cAMP levels remained unaffected. MK571 selectively reduced extracellular cGMP levels. These findings shed light on the role of MRP4 transporters in the porcine bladder, opening avenues for further research into bladder disorders.

Recent Advances in Drug Delivery Strategies for High-Risk BCG-Unresponsive Non-Muscle Invasive Bladder Cancer: A Brief Review from 2018 to 2024

High-risk BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) is a condition that is typically treated with Bacillus Calmette-Guérin (BCG) therapy. Unfortunately, NMIBC is characterized by high recurrence, with a significant percentage of BCG patients ultimately requiring radical cystectomy. As a consequence, the development of effective new therapies to avoid RC has become a rapidly evolving field to address this unmet clinical need. To date, three biologics-Keytruda, Adstiladrin, and Anktiva-have been approved by the FDA, and multiple drug modalities, particularly gene therapies, have shown promising results in clinical trials. Advances in drug delivery strategies, such as targeted delivery, sustained release, and permeabilization of protective layers, are critical in overcoming the challenges posed by therapeutic intervention in bladder cancer. This review focuses on high-risk BCG-unresponsive NMIBC therapies that have been or are currently being investigated in clinical trials, offering a broad overview of the delivery system designs and up-to-date clinical outcomes that have been reported as of July 2024. It aims to inform the development of future drug delivery systems for second-line therapies in high-risk BCG-unresponsive NMIBC.

Emerging molecular therapies in the treatment of bladder cancer

Bladder cancer is a leading cancer type in men. The complexity of treatment in late-stage bladder cancer after systemic spread through the lymphatic system highlights the importance of modulating disease-free progression as early as possible in cancer staging. With current therapies relying on previous standards, such as platinum-based chemotherapeutics and immunomodulation with Bacillus Calmette-Guerin, researchers, and clinicians are looking for targeted therapies to stop bladder cancer at its source early in progression. A new era of molecular therapies that target specific features upregulated in bladder cancer cell lines is surfacing, which may be able to provide clinicians and patients with better control of disease progression. Here, we discuss multiple emerging therapies including immune checkpoint inhibitors of the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway, antibody-drug conjugates, modulation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) cell proliferation pathway, chimeric antigen receptor T-cell therapy, and fibroblast growth factor receptor targeting. Together, these modern treatments provide potentially promising results for bladder cancer patients with the possibility of increasing remission and survival rates.

A Dynamic Interplay of Innate Immune Responses During Urinary Tract Infection

Urinary tract infections (UTIs) represent one of the most prevalent bacterial infections globally, manifesting in diverse clinical phenotypes with varying degrees of severity and complications. The mechanisms underlying UTIs are gradually being elucidated, leading to an enhanced understanding of the immune responses involved. Innate immune cells play a crucial defensive role against uropathogenic bacteria through various mechanisms. Despite their significant contributions to host defense, these cells often fail to achieve complete clearance of uropathogens, necessitating the frequent prescription of antibiotics for UTI patients. However, the persistence of infections and related pathological symptoms in the absence of innate immune cells in animal models underscore the importance of innate immunity in UTIs. Therefore, the host protective functions of innate immune cells, including neutrophils, macrophages, mast cells, NK cells, innate lymphoid cells, and γδ T cells, are delicately coordinated and timely regulated by a variety of cytokines to ensure successful pathogen clearance.

Pictorial review of multiparametric MRI in bladder urothelial carcinoma with variant histology: pearls and pitfalls

Bladder cancer (BC), predominantly comprising urothelial carcinomas (UCs), ranks as the tenth most common cancer worldwide. UCs with variant histology (variant UC), including squamous differentiation, glandular differentiation, plasmacytoid variant, micropapillary variant, sarcomatoid variant, and nested variant, accounting for 5-10% of cases, exhibit more aggressive and advanced tumor characteristics compared to pure UC. The Vesical Imaging-Reporting and Data System (VI-RADS), established in 2018, provides guidelines for the preoperative evaluation of muscle-invasive bladder cancer (MIBC) using multiparametric magnetic resonance imaging (mpMRI). This technique integrates T2-weighted imaging (T2WI), dynamic contrast-enhanced (DCE)-MRI, and diffusion-weighted imaging (DWI) to distinguish MIBC from non-muscle-invasive bladder cancer (NMIBC). VI-RADS has demonstrated high diagnostic performance in differentiating these two categories for pure UC. However, its accuracy in detecting muscle invasion in variant UCs is currently under investigation. These variant UCs are associated with a higher likelihood of disease recurrence and require precise preoperative assessment and immediate surgical intervention. This review highlights the potential value of mpMRI for different variant UCs and explores the clinical implications and prospects of VI-RADS in managing these patients, emphasizing the need for careful interpretation of mpMRI examinations including DCE-MRI, particularly given the heterogeneity and aggressive nature of variant UCs. Additionally, the review addresses the fundamental MRI reading procedures, discusses potential causes of diagnostic errors, and considers future directions in the use of artificial intelligence and radiomics to further optimize the bladder MRI protocol.

RNA-seq gene expression profiling of the bladder in a mouse model of urogenital schistosomiasis

Background

Parasitic flatworms of the Schistosoma genus cause schistosomiasis, which affects over 230 million people. Schistosoma haematobium causes the urogenital form of schistosomiasis (UGS), which can lead to hematuria, fibrosis, and increased risk of secondary infections by bacteria or viruses. UGS is also linked to bladder cancer. To understand the bladder pathology during S. haematobium infection, our group previously developed a mouse model that involves the injection of S. haematobium eggs into the bladder wall. Using this model, we studied changes in epigenetics profile, as well as changes in gene and protein expression in the host bladder tissues. In the current study, we expand upon this work by examining the expression level of both host and parasite genes using RNA sequencing (RNA-seq) in the mouse bladder wall injection model of S. haematobium infection.

Methods

We used a mouse model of S. haematobium infection in which parasite eggs or vehicle control were injected into the bladder walls of female BALB/c mice. RNA-seq was performed on the RNA isolated from the bladders four days after bladder wall injection.

Results/Conclusions

RNA-seq analysis of egg- and vehicle control-injected bladders revealed the differential expression of 1025 mouse genes in the egg-injected bladders, including genes associated with cellular infiltration, immune cell chemotaxis, cytokine signaling, and inflammation We also observed the upregulation of immune checkpoint-related genes, which suggests that while the infection causes an inflammatory response, it also dampens the response to avoid excessive inflammation-related damage to the host. Identifying these changes in host signaling and immune responses improves our understanding of the infection and how it may contribute to the development of bladder cancer. Analysis of the differential gene expression of the parasite eggs between bladder-injected versus uninjected eggs revealed 119 S. haematobium genes associated with transcription, intracellular signaling, and metabolism. The analysis of the parasite genes also revealed fewer transcript reads compared to that found in the analysis of mouse genes, highlighting the challenges of studying parasite egg biology in the mouse model of S. haematobium infection.

Mitigating candidiasis with acarbose by targeting Candida albicans α-glucosidase: in-silico, in-vitro and transcriptomic approaches

Biofilm-associated candidiasis poses a significant challenge in clinical settings due to the limited effectiveness of existing antifungal treatments. The challenges include increased pathogen virulence, multi-drug resistance, and inadequate penetration of antimicrobials into biofilm structures. One potential solution to this problem involves the development of novel drugs that can modulate fungal virulence and biofilm formation, which is essential for pathogenesis. Resistance in Candida albicans is initiated by morphological changes from yeast to hyphal form. This transition triggers a series of events such as cell wall elongation, increased adhesion, invasion of host tissues, pathogenicity, biofilm formation, and the initiation of an immune response. The cell wall is a critical interface for interactions with host cells, primarily through various cell wall proteins, particularly mannoproteins. Thus, cell wall proteins and enzymes are considered potential antifungal targets. In this regard, we explored α-glucosidase as our potential target which plays a crucial role in processing mannoproteins. Previous studies have shown that inhibition of α-glucosidase leads to defects in cell wall integrity, reduced adhesion, diminished secretion of hydrolytic enzymes, alterations in immune recognition, and reduced pathogenicity. Since α-glucosidase, primarily converts carbohydrates, our study focuses on FDA-approved carbohydrate mimic drugs (Glycomimetics) with well-documented applications in various biological contexts. Through virtual screening of 114 FDA-approved carbohydrate-based drugs, a pseudo-sugar Acarbose, emerged as a top hit. Acarbose is known for its pharmacological potential in managing type 2 diabetes mellitus by targeting α-glucosidase. Our preliminary investigations indicate that Acarbose effectively inhibits C. albicans biofilm formation, reduces virulence, impairs morphological switching, and hinders the adhesion and invasion of host cells, all at very low concentrations in the nanomolar range. Furthermore, transcriptomic analysis reveals the mechanism of action of Acarbose, highlighting its role in targeting α-glucosidase.

Cranberry Polyphenols and Prevention against Urinary Tract Infections: New Findings Related to the Integrity and Functionality of Intestinal and Urinary Barriers

This work seeks to generate new knowledge about the mechanisms underlying the protective effects of cranberry against urinary tract infections (UTI). Using Caco-2 cells grown in Transwell inserts as an intestinal barrier model, we found that a cranberry-derived digestive fluid (containing 135 ± 5 mg of phenolic compounds/L) increased transepithelial electrical resistance with respect to control (ΔTEER = 54.5 Ω cm2) and decreased FITC-dextran paracellular transport by about 30%, which was related to the upregulation of the gene expression of tight junction (TJ) proteins (i.e., occludin, zonula occludens-1 [ZO-1], and claudin-2) (∼3-4-fold change with respect to control for claudin-2 and ∼2-3-fold for occludin and ZO-1). Similar protective effects, albeit to a lesser extent, were observed when Caco-2 cells were previously infected with uropathogenic Escherichia coli (UPEC). In a urinary barrier model comprising T24 cells grown in Transwell inserts and either noninfected or UPEC-infected, treatments with the cranberry-derived phenolic metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and phenylacetic acid (PAA) (250 μM) also promoted favorable changes in barrier integrity and permeability. In this line, incubation of noninfected T24 cells with these metabolites induced positive regulatory effects on claudin-2 and ZO-1 expression (∼3.5- and ∼2-fold change with respect to control for DOPAC and ∼1.5- and >2-fold change with respect to control for PAA, respectively). Overall, these results suggest that the protective action of cranberry polyphenols against UTI might involve molecular mechanisms related to the integrity and functionality of the urothelium and intestinal epithelium.

Advances in 3D bioprinting for urethral tissue reconstruction

Urethral conditions affect children and adults, increasing the risk of urinary tract infections, voiding and sexual dysfunction, and renal failure. Current tissue replacements differ from healthy urethral tissues in structural and mechanical characteristics, causing high risk of postoperative complications. 3D bioprinting can overcome these limitations through the creation of complex, layered architectures using materials with location-specific biomechanical properties. This review highlights prior research and describes the potential for these emerging technologies to address ongoing challenges in urethral tissue engineering, including biomechanical and structural mismatch, lack of individualized repair solutions, and inadequate wound healing and vascularization. In the future, the integration of 3D bioprinting technology with advanced biomaterials, computational modeling, and 3D imaging could transform personalized urethral surgical procedures.

Urease-powered nanobots for radionuclide bladder cancer therapy

Bladder cancer treatment via intravesical drug administration achieves reasonable survival rates but suffers from low therapeutic efficacy. To address the latter, self-propelled nanoparticles or nanobots have been proposed, taking advantage of their enhanced diffusion and mixing capabilities in urine when compared with conventional drugs or passive nanoparticles. However, the translational capabilities of nanobots in treating bladder cancer are underexplored. Here, we tested radiolabelled mesoporous silica-based urease-powered nanobots in an orthotopic mouse model of bladder cancer. In vivo and ex vivo results demonstrated enhanced nanobot accumulation at the tumour site, with an eightfold increase revealed by positron emission tomography in vivo. Label-free optical contrast based on polarization-dependent scattered light-sheet microscopy of cleared bladders confirmed tumour penetration by nanobots ex vivo. Treating tumour-bearing mice with intravesically administered radio-iodinated nanobots for radionuclide therapy resulted in a tumour size reduction of about 90%, positioning nanobots as efficient delivery nanosystems for bladder cancer therapy.

Comprehensive analysis of human tissues reveals unique expression and localization patterns of HSF1 and HSF2

Heat shock factors (HSFs) are the main transcriptional regulators of the evolutionarily conserved heat shock response. Beyond cell stress, several studies have demonstrated that HSFs also contribute to a vast variety of human pathologies, ranging from metabolic diseases to cancer and neurodegeneration. Despite their evident role in mitigating cellular perturbations, the functions of HSF1 and HSF2 in physiological proteostasis have remained inconclusive. Here, we analyzed a comprehensive selection of paraffin-embedded human tissue samples with immunohistochemistry. We demonstrate that both HSF1 and HSF2 display distinct expression and subcellular localization patterns in benign tissues. HSF1 localizes to the nucleus in all epithelial cell types, whereas nuclear expression of HSF2 was limited to only a few cell types, especially the spermatogonia and the urothelial umbrella cells. We observed a consistent and robust cytoplasmic expression of HSF2 across all studied smooth muscle and endothelial cells, including the smooth muscle cells surrounding the vasculature and the high endothelial venules in lymph nodes. Outstandingly, HSF2 localized specifically at cell-cell adhesion sites in a broad selection of tissue types, such as the cardiac muscle, liver, and epididymis. To the best of our knowledge, this is the first study to systematically describe the expression and localization patterns of HSF1 and HSF2 in benign human tissues. Thus, our work expands the biological landscape of these factors and creates the foundation for the identification of specific roles of HSF1 and HSF2 in normal physiological processes.

The effect of myeloablative radiation on urinary bladder mast cells

Radiation-induced cystitis is an inflammatory condition affecting the urinary bladder, which can develop as a side effect of abdominopelvic radiotherapy, specifically external-beam radiation therapy or myeloablative radiotherapy. A possible involvement of mast cells in the pathophysiology of radiation-induced cystitis has been indicated in cases of external-beam radiation therapy; however, there is no evidence that these findings apply to the myeloablative aetiology. As such, this study investigated potential changes to urinary bladder mast cell prevalence when exposed to myeloablative radiation. Lethally irradiated C57BL/6J mice that received donor rescue bone marrow cells exhibited an increased mast cell frequency amongst host leukocytes 1 week following irradiation. By 4 weeks, no significant difference in either frequency or cell density was observed. However mast cell diameter was smaller, and a significant increase in mast cell number in the adventitia was observed. This study highlights that mast cells constitute a significant portion of the remaining host leukocyte population following radiation exposure, with changes to mast cell distribution and decreased cell diameter four weeks following radiation-induced injury.

A new role for IFRD1 in regulation of ER stress in bladder epithelial homeostasis

A healthy bladder requires the homeostatic maintenance of and rapid regeneration of urothelium upon stress/injury/infection. Several factors have been identified to play important roles in urothelial development, injury and disease response, however, little is known about urothelial regulation at homeostasis. Here, we identify a new role for IFRD1, a stress-induced gene that has recently been demonstrated to play a critical role in adult tissue proliferation and regeneration, in maintenance of urothelial function/ homeostasis in a mouse model. We show that the mouse bladder expresses IFRD1 at homeostasis and its loss alters the global transcriptome of the bladder with significant accumulation of cellular organelles including multivesicular bodies with undigested cargo, lysosomes and mitochondria. We demonstrate that IFRD1 interacts with several mRNA-translation-regulating factors in human urothelial cells and that the urothelium of Ifrd1-/- mice reveal decreased global translation and enhanced endoplasmic reticulum (ER) stress response. Ifrd1-/- bladders have activation of the unfolded protein response (UPR) pathway, specifically the PERK arm, with a concomitant increase in oxidative stress and spontaneous exfoliation of urothelial cells. Further, we show that such increase in cell shedding is associated with a compensatory proliferation of the basal cells but impaired regeneration of superficial cells. Finally, we show that upon loss of IFRD1, mice display aberrant voiding behavior. Thus, we propose that IFRD1 is at the center of many crucial cellular pathways that work together to maintain urothelial homeostasis, highlighting its importance as a target for diagnosis and/or therapy in bladder conditions.

BCG induced lower urinary tract symptoms during treatment for NMIBC-Mechanisms and management strategies

Non-muscle invasive bladder cancer (NMIBC) accounts for ~70-75% of total bladder cancer tumors and requires effective early intervention to avert progression. The cornerstone of high-risk NMIBC treatment involves trans-urethral resection of the tumor followed by intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. However, BCG therapy is commonly accompanied by significant lower urinary tract symptoms (LUTS) including urinary urgency, urinary frequency, dysuria, and pelvic pain which can undermine treatment adherence and clinical outcomes. Despite this burden, the mechanisms underlying the development of BCG-induced LUTS have yet to be characterized. This review provides a unique perspective on the mechanisms thought to be responsible for the development of BCG-induced LUTS by focussing on the sensory nerves responsible for bladder sensory transduction. This review focuses on how the physiological response to BCG, including inflammation, urothelial permeability, and direct interactions between BCG and sensory nerves could drive bladder afferent sensitization leading to the development of LUTS. Additionally, this review provides an up-to-date summary of the latest clinical data exploring interventions to relieve BCG-induced LUTS, including therapeutic targeting of bladder contractions, inflammation, increased bladder permeability, and direct inhibition of bladder sensory signaling. Addressing the clinical burden of BCG-induced LUTS holds significant potential to enhance patient quality of life, treatment compliance, and overall outcomes in NMIBC management. However, the lack of knowledge on the pathophysiological mechanisms that drive BCG-induced LUTS has limited the development of novel and efficacious therapeutic options. Further research is urgently required to unravel the mechanisms that drive BCG-induced LUTS.

Progress and challenges in intravesical drug delivery

INTRODUCTION

Intravesical drug delivery (IDD) has gained recognition as a viable approach for treating bladder-related diseases over the years. However, it comes with its set of challenges, including voiding difficulties and limitations in mucosal and epithelial penetration. These challenges lead to drug dilution and clearance, resulting in poor efficacy. Various strategies for drug delivery have been devised to overcome these issues, all aimed at optimizing drug delivery. Nevertheless, there has been minimal translation to clinical settings.

AREAS COVERED

This review provides a detailed description of IDD, including its history, advantages, and challenges. It also explores the physical barriers encountered in IDD, such as voiding, mucosal penetration, and epithelial penetration, and discusses current strategies for overcoming these challenges. Additionally, it offers a comprehensive roadmap for advancing IDD into clinical trials.

EXPERT OPINION

Physical bladder barriers and limitations of conventional treatments result in unsatisfactory efficacy against bladder diseases. Nevertheless, substantial recent efforts in this field have led to significant progress in overcoming these challenges and have raised important attributes for an optimal IDD system. However, there is still a lack of well-defined steps in the workflow to optimize the IDD system for clinical settings, and further research is required to establish more comprehensive in vitro and in vivo models to expedite clinical translation.

A human urothelial microtissue model reveals shared colonization and survival strategies between uropathogens and commensals

Urinary tract infection is among the most common infections worldwide, typically studied in animals and cell lines with limited uropathogenic strains. Here, we assessed diverse bacterial species in a human urothelial microtissue model exhibiting full stratification, differentiation, innate epithelial responses, and urine tolerance. Several uropathogens invaded intracellularly, but also commensal Escherichia coli, suggesting that invasion is a shared survival strategy, not solely a virulence hallmark. The E. coli adhesin FimH was required for intracellular bacterial community formation, but not for invasion. Other shared lifestyles included filamentation (Gram-negatives), chaining (Gram-positives), and hijacking of exfoliating cells, while biofilm-like aggregates were formed mainly with Pseudomonas and Proteus. Urothelial cells expelled invasive bacteria in Rab-/LC3-decorated structures, while highly cytotoxic/invasive uropathogens, but not commensals, disrupted host barrier function and strongly induced exfoliation and cytokine production. Overall, this work highlights diverse species-/strain-specific infection strategies and corresponding host responses in a human urothelial microenvironment, providing insights at the microtissue, cell, and molecular level.

Intracellular remodeling associated with endoplasmic reticulum stress modifies biomechanical compliance of bladder cells

Bladder cells face a challenging biophysical environment: mechanical cues originating from urine flow and regular contraction to enable the filling voiding of the organ. To ensure functional adaption, bladder cells rely on high biomechanical compliance, nevertheless aging or chronic pathological conditions can modify this plasticity. Obviously the cytoskeletal network plays an essential role, however the contribution of other, closely entangled, intracellular organelles is currently underappreciated. The endoplasmic reticulum (ER) lies at a crucial crossroads, connected to both nucleus and cytoskeleton. Yet, its role in the maintenance of cell mechanical stability is less investigated. To start exploring these aspects, T24 bladder cancer cells were treated with the ER stress inducers brefeldin A (10-40nM BFA, 24 h) and thapsigargin (0.1-100nM TG, 24 h). Without impairment of cell motility and viability, BFA and TG triggered a significant subcellular redistribution of the ER; this was associated with a rearrangement of actin cytoskeleton. Additional inhibition of actin polymerization with cytochalasin D (100nM CytD) contributed to the spread of the ER toward cell periphery, and was accompanied by an increase of cellular stiffness (Young´s modulus) in the cytoplasmic compartment. Shrinking of the ER toward the nucleus (100nM TG, 2 h) was related to an increased stiffness in the nuclear and perinuclear areas. A similar short-term response profile was observed also in normal human primary bladder fibroblasts. In sum, the ER and its subcellular rearrangement seem to contribute to the mechanical properties of bladder cells opening new perspectives in the study of the related stress signaling cascades. Video Abstract.

Animal models of interstitial cystitis/bladder pain syndrome

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a chronic disorder characterized by pelvic and/or bladder pain, along with lower urinary tract symptoms that have a significant impact on an individual's quality of life. The diverse range of symptoms and underlying causes in IC/BPS patients pose a significant challenge for effective disease management and the development of new and effective treatments. To facilitate the development of innovative therapies for IC/BPS, numerous preclinical animal models have been developed, each focusing on distinct pathophysiological components such as localized urothelial permeability or inflammation, psychological stress, autoimmunity, and central sensitization. However, since the precise etiopathophysiology of IC/BPS remains undefined, these animal models have primarily aimed to replicate the key clinical symptoms of bladder hypersensitivity and pain to enhance the translatability of potential therapeutics. Several animal models have now been characterized to mimic the major symptoms of IC/BPS, and significant progress has been made in refining these models to induce chronic symptomatology that more closely resembles the IC/BPS phenotype. Nevertheless, it's important to note that no single model can fully replicate all aspects of the human disease. When selecting an appropriate model for preclinical therapeutic evaluation, consideration must be given to the specific pathology believed to underlie the development of IC/BPS symptoms in a particular patient group, as well as the type and severity of the model, its duration, and the proposed intervention's mechanism of action. Therefore, it is likely that different models will continue to be necessary for preclinical drug development, depending on the unique etiology of IC/BPS being investigated.

Neo-Adjuvant immunotherapies: Bladder cancer as a platform for drug development targeting mucosal immunity

Bacillus Calmette-Guerin (BCG) is a live attenuated Mycobacterium bovis strain, originally developed as a vaccine against tuberculosis. It is also the only bacterial cancer therapy approved by the US Food & Drug Administration for clinical use. BCG is delivered in the bladder, shortly after tumour resection, for patients with high-risk non-muscle invasive bladder cancer (NMIBC). Modulating mucosal immunity by exposing the urothelium to intravesical BCG has been the main therapeutic strategy for high-risk NMIBC over the last three decades. Thus, BCG provides a benchmark for the clinical development of bacteria-or other live attenuated pathogens-as cancer therapy. Currently, a myriad of immuno-oncology compounds is under clinical evaluation in BCG-unresponsive and BCG-naïve patients as an alternative therapy in the context of worldwide BCG shortages. For patients with non-metastatic muscle-invasive bladder cancer (MIBC), studies investigating neoadjuvant immunotherapy with either anti-PD-1/PD-L1 monoclonal antibodies in monotherapy or in combination with anti-CTLA-4 monoclonal antibodies have shown overall efficacy and acceptable safety profiles prior to radical cystectomy. Emerging clinical investigations are testing synergistic approaches by combining intravesical delivery of drugs with systemic immune checkpoint blockades in the neoadjuvant setting for patients with MIBC. Such novel strategy aims to prime a local anti-tumour immunity and reduce distant metastatic relapses by enhancing a systemic adaptive anti-tumour immune response. Here, we present and discuss some of the most promising clinical trials developing such novel therapeutic approaches.

Hydrogels for Mucosal Drug Delivery

Mucosal tissues are often a desirable site of drug action to treat disease and engage the immune system. However, systemically administered drugs suffer from limited bioavailability in mucosal tissues where technologies to enable direct, local delivery to these sites would prove useful. In this Spotlight on Applications article, we discuss hydrogels as an attractive means for local delivery of therapeutics to address a range of conditions affecting the eye, nose, oral cavity, gastrointestinal, urinary bladder, and vaginal tracts. Considering the barriers to effective mucosal delivery, we provide an overview of the key parameters in the use of hydrogels for these applications. Finally, we highlight recent work demonstrating their use for inflammatory and infectious diseases affecting these tissues.

Onabotulinum Toxin A Intradetrusor Injections in Children with Neurogenic Lower Urinary Tract Dysfunction: Long-Term Histological Effects on the Bladder Wall

BACKGROUND

In the last twenty-five years, Onabotulinum Toxin A (BTX-A) has gained increasing popularity for neurogenic lower urinary tract dysfunction (NLUTD) treatment. To maintain its efficacy, repeated BTX-A intradetrusor injections are required over time, with unknown effects on the bladder wall in children. The aim of this paper is to report long-term effects on the bladder wall in children treated with BTX-A.

METHODS

Children with NLUTD not responsive to anticholinergics were treated with BTX-A, according to our protocol, with bladder wall control using endoscopic cold-cup biopsy. Specimens were evaluated considering edema, chronic inflammation, and fibrosis.

RESULTS

Of the 230 patients treated from 1997 to 2022, we considered only specimens obtained in patients who had received ≥5 treatments (36 children), considered as the threshold to evaluate clinical effectiveness on long-term treatment with BTX-A. Most of them had congenital NLUTD (25 patients) and detrusor overactivity (27 patients). In all, increased edema and chronic inflammation with reduced fibrosis over time was reported; these data were not statistically significant. No difference was observed between patients with congenital and acquired diseases.

CONCLUSIONS

Repeated intradetrusor BTX-A injections are not related to significant histological alterations in children, similarly with adults, and repeated injections could be considered safe.