Prevalence of non-neurogenic male lower urinary tract symptoms after kidney transplantation

OBJECTIVE

This review investigates the prevalence of male non-neurogenic lower urinary tract symptoms (LUTS) after renal transplant, as kidney transplantation is a transformative intervention for patients with end-stage renal disease significantly enhancing quality of life that might be diminished by LUTS.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. A systematic search in the PubMed and Scopus databases was performed using specific terms. Inclusion criteria considered male kidney transplant recipients, analysing outcomes in English-language studies. Discrepancies were resolved by consultation.

RESULTS

Among 18 studies involving 29 086 recipients, the prevalence of non-neurogenic LUTS ranged from 5.8% to 33.0%. Studies predominantly used the International Prostate Symptom Score for evaluation. Surgical interventions, mostly for benign prostatic obstruction, ranged from 2.5% to 20.0%. Voiding and post-micturition symptoms were under-represented.

CONCLUSION

This review found varied non-neurogenic LUTS prevalence and characteristics in male kidney transplant recipients, emphasising the need for standardised assessments, prospective studies, and improved understanding of LUTS mechanisms. Enhanced knowledge can guide interventions, additionally benefiting recipient quality of life.

Myogenic Underactive Bladder and Heart Failure Resemblance: A Novel Role for SGLT2 Inhibition?

The heart and bladder share physiological biomechanical determinants of contraction. Heart failure (HF) and myogenic underactive bladder (mUAB) also share similarities in their pathophysiology. In both cases there is muscle injury that is directly linked to disease stage. In the final stage, both myocardium and detrusor show marked fibrosis and lower contractility. While HF has an established pharmacological treatment, there are still no effective drugs for mUAB. This mini-review explores the similarities between HF and mUAB and suggests that, as in HF, SGLT2 inhibitors may also have a beneficial role in mUAB. PATIENT SUMMARY: To date, there is no treatment for underactive bladder caused by problems with the bladder muscle (mUAB). We review similarities between this condition and heart failure and hypothesize that a recent drug class with striking results in heart failure might also have a beneficial role in mUAB.

Treatment of idiopathic overactive bladder with botulinum toxin: real-life results and patients' expectations

Background

Overactive bladder (OAB) is a prevalent syndrome affecting 11% to 16% of the adult population. When first-line pharmacological therapy is not effective, intradetrusorial injections of onabotulinumtoxinA (BTX-A) might have an important role in controlling symptoms. The main aim of this study was to access both the efficacy and safety of intradetrusor injections of 100U BTX-A in real clinical practice, among women with idiopathic OAB (iOAB).

Methods

Retrospective study, based on clinical diaries in 136 iOAB female patients, with or without urinary incontinence, submitted to BTX-A injections, between 2005 and 2018 in a tertiary university hospital. Positive response was considered only when the patient mentioned she had great improvement after the injection, otherwise, it was considered negative.

Results

A positive response was obtained in 90 patients (66%) after the first injection. Women with a positive response after the first treatment had 7.5 times more chances to improve with the second (P = .01). Discontinuation of the therapy after the first injection was neither dependent on the presence of incontinence at baseline (P = .73) nor it was related to age (P = .6). On univariate analyses, none of the parameters evaluated was useful of predicting successful response, although there was a trend in women who had had a previous midurethral sling surgery for stress urinary incontinence, to have a lower chance of having a positive response after the first injection (P = .06).Thirty-nine women (29%) had at least 1 adverse event, urinary tract infection, and straining to void were the most frequent. Women above 65 years old had less risk of developing a urinary tract infection (P = .04).

Conclusion

In real clinical practice, BTX-A injection is an effective (66%) and safe treatment, capable of improving quality of life. Moreover, responding to the first injection seems to predict good clinical outcomes in the second treatment. This procedure can be done with minimal restrictions.

DYNLT1 gene expression is downregulated in whole blood of patients at different Huntington's disease stages

Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG nucleotide expansion, which encodes the amino acid glutamine, in the huntingtin gene. HD is characterized by motor, cognitive, and psychiatric dysfunctions. In a previous study, we showed by qPCR that some genes altered in an HD mouse model were also altered in blood of HD patients. These alterations were mainly with respect to the dynein family. Therefore, this study aimed to investigate whether dynein light chain Tctex type 1 (DYNLT1) is altered in HD patients and if there is a correlation between DYNLT1 gene expression changes and disease progression. We assessed the DYNLT1 gene expression in the blood of 19 HD patients and 20 healthy age-matched controls. Also, in 6 of these patients, we analyzed the DYNLT1 expression at two time points, 3 years apart. The DYNLT1 gene expression in the whole blood of HD patients was significantly downregulated and this difference was widened in later stages. These data suggest that DYNLT1 could emerge as a peripheral prognostic indicator in HD and, also, might be a target for potential intervention in the future.

Treatment of Non-neurogenic Lower Urinary Tract Symptoms-A Review of Key Publications from 2018 Onward

CONTEXT

A considerable number of studies addressing the management of lower urinary tract symptoms (LUTS) have been published since 2018.

OBJECTIVE

To review the key studies involving pharmacological and neuromodulation treatment of LUTS published from 2018 onward.

EVIDENCE ACQUISITION

We followed the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statement. We conducted an Embase/PubMed search of English literature with the words "OAB" or "LUTS" matched with several different treatment modalities. The search ranged between January 2018 and January 2020. All retrieved papers were first reviewed by title and abstract, yielding a total of 236 papers. Additional manuscripts, such as those presented at major meetings, were also included. After revision, 46 publications were included.

EVIDENCE SYNTHESIS

Papers on β3-adrenoreceptor agonists were most abundant. The efficacy and safety of mirabegron in monotherapy and combination therapy were further confirmed by large observational studies and randomized control trials, including one carried out in elderly patients. The use of vibegron for overactive bladder (OAB) was effective and safe in pivotal clinical trials. More database analyses confirm the risk of dementia associated with long-term use of anticholinergics. Onabotulinum toxinA (OnabotA) and sacral neuromodulation provided similar improvement for incontinence in OAB patients at a 2-yr follow-up. Retrospective studies show that OnabotA is effective in men with OAB. New subcutaneous or transcutaneous devices for tibial nerve stimulation were investigated. The potential role of gene therapy in LUTS was assessed in a pilot study.

CONCLUSIONS

Important progresses occurred in the pharmacological and neuromodulation treatments of LUTS, which may change clinical practice. Inoculation of gene vectors was investigated for the first time.

PATIENT SUMMARY

The investigation in the therapeutic field of lower urinary tract symptoms is active. The search for the best option for each patient continues. This systematic review summarizes the findings of the most recent and relevant studies in the field.

The cannabinoid agonist WIN-2 affects acquisition but not consolidation of a spatial information in training and retraining processes: Relation with transcriptional regulation of the endocannabinoid system?

The endocannabinoid system is capable of modulating multiple physiological brain functions including learning and memory. Moreover, there is evidence that the processes of acquisition and consolidation have distinct biological basis. We used the cannabinoid agonist WIN 55,212-2 (WIN-2) to investigate whether chronic CB1 activation affects acquisition and consolidation differently by evaluating gene expression in the hippocampus (HIP) and prefrontal cortex (PFC). Swiss mice were treated with WIN-2 (2 mg/kg) and submitted to the Morris water maze to evaluate different aspects of memory. We observed short-term memory impairment in acquisition of the spatial task while consolidation remained unchanged. In the PFC, animals that received WIN-2 prior to the task exhibited increased expression of the 2-AG synthesis enzyme diacylglycerol lipase and decreased levels of the degradation enzyme monoacylglycerol lipase, while mice that were treated after the task for the evaluation of consolidation exhibited the opposite profile. With respect to genes related to AEA metabolism, no correlation between the molecular and behavioral data could be established. In this sense, the cognitive impairment in the acquisition promoted by WIN-2 treatment may be related to a possible increase in the concentration of 2-AG in the PFC. Overall, this study confirms the relevance of the endocannabinoid system in the modulation of cognitive processes. A better understanding of the mechanisms underlying endocannabinoids roles in cognition could provide guidance for the development of treatments to reduce the cognitive deficits caused by drug abuse.

Efficacy and Safety of OnabotulinumtoxinA in Patients with Urinary Incontinence Due to Neurogenic Detrusor Overactivity: Update of the Pivotal Randomised, Double-blind, Placebo-controlled Trials

Bladder injections of 200U onabotulinumtoxinA have similar efficacy in the treatment of urinary incontinence in patients with multiple sclerosis or spinal cord injury. The effect is maintained in the long term without significant adverse events.

Reduced expression of the vesicular acetylcholine transporter causes learning deficits in mice

Storage of acetylcholine in synaptic vesicles plays a key role in maintaining cholinergic function. Here we used mice with a targeted mutation in the vesicular acetylcholine transporter (VAChT) gene that reduces transporter expression by 40% to investigate cognitive processing under conditions of VAChT deficiency. Motor skill learning in the rotarod revealed that VAChT mutant mice were slower to learn this task, but once they reached maximum performance they were indistinguishable from wild-type mice. Interestingly, motor skill performance maintenance after 10 days was unaffected in these mutant mice. We also tested whether reduced VAChT levels affected learning in an object recognition memory task. We found that VAChT mutant mice presented a deficit in memory encoding necessary for the temporal order version of the object recognition memory, but showed no alteration in spatial working memory, or spatial memory in general when tested in the Morris water maze test. The memory deficit in object recognition memory observed in VAChT mutant mice could be reversed by cholinesterase inhibitors, suggesting that learning deficits caused by reduced VAChT expression can be ameliorated by restoring ACh levels in the synapse. These data indicate an important role for cholinergic tone in motor learning and object recognition memory.

The hemicholinium-3 sensitive high affinity choline transporter is internalized by clathrin-mediated endocytosis and is present in endosomes and synaptic vesicles

Synthesis of acetylcholine depends on the plasma membrane uptake of choline by a high affinity choline transporter (CHT1). Choline uptake is regulated by nerve impulses and trafficking of an intracellular pool of CHT1 to the plasma membrane may be important for this regulation. We have generated a hemagglutinin (HA) epitope tagged CHT1 to investigate the organelles involved with intracellular trafficking of this protein. Expression of CHT1-HA in HEK 293 cells establishes Na+-dependent, hemicholinium-3 sensitive high-affinity choline transport activity. Confocal microscopy reveals that CHT1-HA is found predominantly in intracellular organelles in three different cell lines. Importantly, CHT1-HA seems to be continuously cycling between the plasma membrane and endocytic organelles via a constitutive clathrin-mediated endocytic pathway. In a neuronal cell line, CHT1-HA colocalizes with the early endocytic marker green fluorescent protein (GFP)-Rab 5 and with two markers of synaptic-like vesicles, VAMP-myc and GFP-VAChT, suggesting that in cultured cells CHT1 is present mainly in organelles of endocytic origin. Subcellular fractionation and immunoisolation of organelles from rat brain indicate that CHT1 is present in synaptic vesicles. We propose that intracellular CHT1 can be recruited during stimulation to increase choline uptake in nerve terminals.

Trafficking of the vesicular acetylcholine transporter in SN56 cells: a dynamin-sensitive step and interaction with the AP-2 adaptor complex

The pathways by which synaptic vesicle proteins reach their destination are not completely defined. Here we investigated the traffic of a green fluorescent protein (GFP)-tagged version of the vesicular acetylcholine transporter (VAChT) in cholinergic SN56 cells, a model system for neuronal processing of this cargo. GFP-VAChT accumulates in small vesicular compartments in varicosities, but perturbation of endocytosis with a dominant negative mutant of dynamin I-K44A impaired GFP-VAChT trafficking to these processes. The protein in this condition accumulated in the cell body plasma membrane and in large vesicular patches therein. A VAChT endocytic mutant (L485A/L486A) was also located at the plasma membrane, however, the protein was not sorted to dynamin I-K44A generated vesicles. A fusion protein containing the VAChT C-terminal tail precipitated the AP-2 adaptor protein complex from rat brain, suggesting that VAChT directly interacts with the endocytic complex. In addition, yeast two hybrid experiments indicated that the C-terminal tail of VAChT interacts with the micro subunit of AP-2 in a di-leucine (L485A/L486A) dependent fashion. These observations suggest that the di-leucine motif regulates sorting of VAChT from the soma plasma membrane through a clathrin dependent mechanism prior to the targeting of the transporter to varicosities.