Aim: To investigate the effect of nerve growth factor (NGF) neutralization on Na channel plasticity of bladder afferent neurons in mice with spinal cord injury (SCI).
Main Methods: Female C57/BL6 mice were randomly divided into spinal intact (SI) group, SCI group and SCI + NGF-Ab group. SCI was induced by spinal cord transection at the Th8/9 level. In SCI + NGF-Ab group, anti-NGF antibodies (10 μg·kg-1 per hour) were continuously administered for 2 weeks using osmotic pumps. Bladder afferent neurons were labelled with Fluoro‑gold (FG) injected into the bladder wall. L6-S1 dorsal root ganglion (DRG) neurons were dissociated and whole-cell patch clamp recordings were performed on FG-labelled neurons. Expression of Nav1.7 and Nav1.8 was examined by immunofluorescent staining.
Key Findings: Whole-cell patch clamp recordings showed that TTX only partially inhibited action potentials (AP) and Na currents of bladder afferent neurons in SI mice, but it almost completely inhibited them in SCI mice. Total and TTX-sensitive Na currents were increased and TTX-resistant currents were decreased in bladder afferent neurons from SCI mice vs. SI mice. These changes in SCI mice were significantly reversed by NGF-antibody treatment. Immunostaining results showed the increased and decreased levels of Nav1.7 and Nav1.8, respectively, in FG-labelled bladder afferent neurons in SCI mice vs. SI mice, which was significantly reversed in SCI + NGF-Ab mice.
Significance: NGF mediates the Na channel plasticity with a shift from TTX-resistant Nav1.8 to TTX-sensitive Nav1.7 in bladder afferent neurons, which could be a possible underlying mechanism of bladder afferent hyperexcitability and detrusor overactivity after SCI.
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http://dx.doi.org/10.1016/j.lfs.2022.120524 | DOI Listing |
Brain Sci
November 2024
Flinders Health and Medical Research Institute (FHMRI), College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia.
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.
View Article and Find Full Text PDFNeurourol Urodyn
December 2024
Desai Sethi Institute of Urology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Aims: To answer the question of whether the bladder itself can to any extent control or modulate the initiation of voiding.
Methods: This subject was discussed at the International Consultation on Incontinence-Research Society (ICI-RS) 2024 conference in Bristol, UK in a proposal session.
Results: Cells in the bladder wall sense the local environment via a diverse array of ion channels and receptors which together provide input to motor-sensory and signal transduction mechanisms.
Int J Mol Sci
November 2024
Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburg, PA 15261, USA.
Sensitization of primary afferents is essential for the development of pain, but the molecular events involved in this process and its reversal are poorly defined. Recent studies revealed that acid-sensing ion channels (ASICs) control the excitability of nociceptors in the urinary bladder. Using genetic and pharmacological tools we show that ASICs are functionally coupled with voltage-gated Ca channels to mediate Ca transients evoked by acidification in sensory neurons.
View Article and Find Full Text PDFJ Spinal Cord Med
December 2024
Department of Traditional Chinese Medicine, Gansu Provincial Hospital of Traditional Chinese Medicine, Lanzhou, People's Republic of China.
Objective: The present study aims to investigate the effect and mechanism of heavy moxibustion (100 moxa-cone) at Sanyin point (the common point of Yin and kidney) on the function of neurogenic bladder (NB) dysfunction in rats with spinal cord injury (SCI).
Methods: Twenty-four male Sprague-Dawley rats were divided into four groups (n = 6): control, NB, NB + Moxibustion, and NB + Moxibustion + YS-49 (PI3 K agonist). The rats in control groups accepted a cut open of the skin, fascia, and muscle.
Nat Rev Urol
December 2024
Research Unit of Urology, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
Neuromodulation has been used in the treatment of various pelvic organ dysfunctions for almost 40 years and several placebo-controlled studies have confirmed its clinical effect. Many neuromodulation methods using different devices and stimulation parameters, targeting different neural structures have been introduced, but only a limited number have been adopted into routine clinical use. A substantial volume of basic research and clinical studies addressing specific effects of neuromodulation in the treatment of overactive bladder (OAB) have been published to date; however, their mechanistic implications have not been comprehensively summarized.
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