BoNT/A in the Urinary Bladder—More to the Story Than Silencing of Cholinergic Nerves

Botulinum neurotoxin (BoNT/A) is an FDA and NICE approved second-line treatment for overactive bladder (OAB) in patients either not responsive or intolerant to anti-cholinergic drugs. BoNT/A acts to weaken muscle contraction by blocking release of the neurotransmitter acetyl choline (ACh) at neuromuscular junctions. However, this biological activity does not easily explain all the observed effects in clinical and non-clinical studies. There are also conflicting reports of expression of the BoNT/A protein receptor, SV2, and intracellular target protein, SNAP-25, in the urothelium and bladder. This review presents the current evidence of BoNT/A’s effect on bladder sensation, potential mechanisms by which it might exert these effects and discusses recent advances in understanding the action of BoNT in bladder tissue.

Therapeutic effect of adipose stromal vascular fraction spheroids for partial bladder outlet obstruction induced underactive bladder

Background: Underactive bladder (UAB) is a common clinical problem but related research is rarely explored. As there are currently no effective therapies, the administration of adipose stromal vascular fraction (ad-SVF) provides a new potential method to treat underactive bladder. Methods: Male Sprague-Dawley rats were induced by partial bladder outlet obstruction (PBOO) for four weeks and randomly divided into three groups: rats treated with PBS (Sham group); rats administrated with ad-SVF (ad-SVF group) and rats performed with ad-SVF spheroids (ad-SVFsp group). After four weeks, urodynamic studies were performed to evaluate bladder functions and all rats were sacrificed for further studies.Results: We observed that the bladder functions and symptoms of UAB were significantly improved in the ad-SVFsp group than that in the Sham group and ad-SVF group. Meanwhile, our data showed that ad-SVF spheroids could remarkably promote angiogenesis, suppress cell apoptosis and stimulate cell proliferation in bladder tissue than that in the other two groups. Moreover, ad-SVF spheroids increased the expression levels of bFGF, HGF and VEGF-A than ad-SVF. IVIS Spectrum small-animal in vivo imaging system revealed that ad-SVF spheroids could increase the retention rate of transplanted cells in bladder tissue. Conclusions: Ad-SVF spheroids improved functions and symptoms of bladder induced by PBOO, which contributes to promote angiogenesis, suppress cell apoptosis and stimulate cell proliferation. Ad-SVF spheroids provide a potential treatment for the future patients with UAB.

The Significance of Biomechanics and Scaffold Structure for Bladder Tissue Engineering

Current approaches for bladder reconstruction surgery are associated with many morbidities. Tissue engineering is considered an ideal approach to create constructs capable of restoring the function of the bladder wall. However, many constructs to date have failed to create a sufficient improvement in bladder capacity due to insufficient neobladder compliance. This review evaluates the biomechanical properties of the bladder wall and how the current reconstructive materials aim to meet this need. To date, limited data from mechanical testing and tissue anisotropy make it challenging to reach a consensus on the native properties of the bladder wall. Many of the materials whose mechanical properties have been quantified do not fall within the range of mechanical properties measured for native bladder wall tissue. Many promising new materials have yet to be mechanically quantified, which makes it difficult to ascertain their likely effectiveness. The impact of scaffold structures and the long-term effect of implanting these materials on their inherent mechanical properties are areas yet to be widely investigated that could provide important insight into the likely longevity of the neobladder construct. In conclusion, there are many opportunities for further investigation into novel materials for bladder reconstruction. Currently, the field would benefit from a consensus on the target values of key mechanical parameters for bladder wall scaffolds.

A Data-Driven Memory-Dependent Modeling Framework for Anomalous Rheology: Application to Urinary Bladder Tissue

We introduce a data-driven fractional modeling framework for complex materials, and particularly bio-tissues. From multi-step relaxation experiments of distinct anatomical locations of porcine urinary bladder, we identify an anomalous relaxation character, with two power-law-like behaviors for short/long long times, and nonlinearity for strains greater than 25%. The first component of our framework is an existence study, to determine admissible fractional viscoelastic models that qualitatively describe linear relaxation. After the linear viscoelastic model is selected, the second stage adds large-strain effects to the framework through a fractional quasi-linear viscoelastic approach for the nonlinear elastic response of the bio-tissue of interest. From single-step relaxation data of the urinary bladder, a fractional Maxwell model captures both short/long-term behaviors with two fractional orders, being the most suitable model for small strains at the first stage. For the second stage, multi-step relaxation data under large strains were employed to calibrate a four-parameter fractional quasi-linear viscoelastic model, that combines a Scott-Blair relaxation function and an exponential instantaneous stress response, to describe the elastin/collagen phases of bladder rheology. Our obtained results demonstrate that the employed fractional quasi-linear model, with a single fractional order in the range α = 0.25–0.30, is suitable for the porcine urinary bladder, producing errors below 2% without need for recalibration over subsequent applied strains. We conclude that fractional models are attractive tools to capture the bladder tissue behavior under small-to-large strains and multiple time scales, therefore being potential alternatives to describe multiple stages of bladder functionality.

Follicular cholecystitis with cholelithiasis – A diagnostic pitfall

Follicular Cholecystitis (FC) is an extremely rare subtype of Chronic Cholecystitis (CC). It is characterized by hyperplastic lymphoid follicles along with prominent germinal centers. It constitutes about 2% of routine cholecystectomies. In this article, we report a case of FC in a 69 years lady. She had abdominal pain, clinically diagnosed as Calculus cholecystitis and managed by laparoscopic cholecystectomy. Grossly, thickening of the gall bladder wall was noted. Histopathological examination revealed gall bladder wall infiltrated by dense lymphoid infiltrate forming lymphoid follicles with prominent germinal centres. Hence, we rendered a diagnosis of FC. The purpose of presenting this case is to make pathologists aware about this entity. One should not mistake this lesion for lymphoma. A careful histopathological examination is diagnostic and Immunohistochemistry may be helpful in difficult cases.Follicular Cholecystitis is extremely rare variant of Chronic cholecystitis. It is characterized by at least 3 Lymphoid Follicles per cm of Gall Bladder tissue with inflammatory infiltrate composed almost exclusively of scattered well-formed Lymphoid Follicles. Pathologist must be familiar with this entity to avoid misdiagnosis of lymphoma.

L-Theanine Protects Bladder Function by Suppressing Chronic Sympathetic Hyperactivity in Spontaneously Hypertensive Rat

Chronic sympathetic hyperactivity is known to affect metabolism and cause various organ damage including bladder dysfunction. In this study, we evaluated whether L-theanine, a major amino acid found in green tea, ameliorates bladder dysfunction induced by chronic sympathetic hyperactivity as a dietary component for daily consumption. Spontaneously hypertensive rats (SHRs), as an animal model of bladder dysfunction, were divided into SHR–water and SHR–theanine groups. After 6 weeks of oral administration, the sympathetic nervous system, bladder function, and oxidative stress of bladder tissue were evaluated. The mean blood pressure, serum noradrenaline level, and media-to-lumen ratio of small arteries in the suburothelium were significantly lower in the SHR–theanine than in the SHR–water group. Micturition interval was significantly longer, and bladder capacity was significantly higher in the SHR–theanine than in the SHR–water group. Bladder strip contractility was also higher in the SHR–theanine than in the SHR–water group. Western blotting of bladder showed that expression of malondialdehyde was significantly lower in the SHR–theanine than in the SHR–water group. These results suggested that orally administered L-theanine may contribute at least partly to the prevention of bladder dysfunctions by inhibiting chronic sympathetic hyperactivity and protecting bladder contractility.

Spheroids of Bladder Smooth Muscle Cells for Bladder Tissue Engineering

Cell-based tissue engineering (TE) has been proposed to improve treatment outcomes in end-stage bladder disease, but TE approaches with 2D smooth muscle cell (SMC) culture have so far been unsuccessful. Here, we report the development of primary bladder-derived 3D SMC spheroids that outperform 2D SMC cultures in differentiation, maturation, and extracellular matrix (ECM) production. Bladder SMC spheroids were compared with 2D cultures using live-dead staining, qRT-PCR, immunofluorescence, and immunoblotting to investigate culture conditions, contractile phenotype, and ECM deposition. The SMC spheroids were viable for up to 14 days and differentiated rather than proliferating. Spheroids predominantly expressed the late myogenic differentiation marker MyH11, whereas 2D SMC expressed more of the general SMC differentiation marker α-SMA and less MyH11. Furthermore, the expression of bladder wall-specific ECM proteins in SMC spheroids was markedly higher. This first establishment and analysis of primary bladder SMC spheroids are particularly promising for TE because differentiated SMCs and ECM deposition are a prerequisite to building a functional bladder wall substitute. We were able to confirm that SMC spheroids are promising building blocks for studying detrusor regeneration in detail and may provide improved function and regenerative potential, contributing to taking bladder TE a significant step forward.

Luteolin Improves Cyclophosphamide-Induced Cystitis through TXNIP/NLRP3 and NF-κB Pathways

Hemorrhagic cystitis is an important complication of cyclophosphamide chemotherapy, and current therapies for the disease are limited. The natural flavonoid luteolin (LUT) has significant anti-inflammatory and antioxidant properties, but its protective effect on cyclophosphamide (CYP)-induced bladder toxicity has yet to be evaluated. This study aims to explore the protective effect of LUT on CYP-induced acute cystitis in rats. Female Sprague-Dawley rats were randomly assigned to the control (CON) group, CON + LUT group, CYP group, and CYP + LUT group. A single intraperitoneal injection of CYP was administered to establish an acute hemorrhagic cystitis model. HE staining was performed to detect the degree of bladder tissue damage, and TUNEL staining was performed to count apoptotic cells. Oxidative stress indicators were measured using commercial kits, and bladder surgery was performed to assess urinary function. The levels of inflammatory cytokines, apoptosis-related indicators, TXNIP/NLRP3 pathway, and NF-κB pathway were detected by western blot. We found that LUT treatment reduced bladder bleeding, congestion, and edema caused by CYP. Compared with the CYP + LUT group, the level of apoptosis was more highly expressed in the CYP group. We also found that caspase-3, caspase-8, and Bax were significantly upregulated and Bcl-2 was downregulated after LUT treatment. In addition, LUT inhibited the activation of NF-κB signal pathway in the rat bladder tissue after CYP exposure. LUT treatment can also reduce the NLRP3 inflammasome (NLRP3, ASC, and caspase-1) and TXNIP in the bladder. Finally, LUT can reduce the increase in the urination frequency and maximum urination pressure caused by cystitis. These results indicate that LUT displays effective anti-inflammatory, antioxidant, and antiapoptotic properties in CYP-induced acute hemorrhagic cystitis rats by inhibiting the TXNIP/NLRP3 and NF-κB pathways. LUT may be a potent therapeutic agent for the prevention and treatment of hemorrhagic cystitis.

A Transcriptional Signature of IL-2 Expanded Natural Killer Cells Predicts More Favorable Prognosis in Bladder Cancer

Activation of natural killer (NK) cell function is regulated by cytokines, such as IL-2, and secreted factors upregulated in the tumor microenvironment, such as platelet-derived growth factor D (PDGF-DD). In order to elucidate a clinical role for these important regulators of NK cell function in antitumor immunity, we generated transcriptional signatures representing resting, IL-2-expanded, and PDGF-DD-activated, NK cell phenotypes and established their abundance in The Cancer Genome Atlas bladder cancer (BLCA) dataset using CIBERSORT. The IL-2-expanded NK cell phenotype was the most abundant in low and high grades of BLCA tumors and was associated with improved prognosis. In contrast, PDGFD expression was associated with numerous cancer hallmark pathways in BLCA tumors compared with normal bladder tissue, and a high tumor abundance of PDGFD transcripts and the PDGF-DD-activated NK cell phenotype were associated with a poor BLCA prognosis. Finally, high tumor expression of transcripts encoding the activating NK cell receptors, KLRK1 and the CD160–TNFRSF14 receptor–ligand pair, was strongly correlated with the IL-2-expanded NK cell phenotype and improved BLCA prognosis. The transcriptional parameters we describe may be optimized to improve BLCA patient prognosis and risk stratification in the clinic and potentially provide gene targets of therapeutic significance for enhancing NK cell antitumor immunity in BLCA.