Study on electroacupuncture at "Ciliao" (BL32) improving stress urinary incontinence in mice by promoting endogenous bone marrow mesenchymal stem cell homing

To investigate whether electroacupuncture at "Ciliao" (BL32) can improve the mitochondrial homeostasis imbalance of periurethral tissues in mice by promoting the homing of endogenous bone marrow mesenchymal stem cell (BMMSC) to the periurethral region of mice, and ultimately improve stress urinary incontinence (SUI), with the aim of providing a reference for the treatment of pelvic floor dysfunction disorders.

In experiment 1, 25 C57BL/6 female mice were randomly divided into the sham operation, model, electroacupuncture, acupuncture, and electrical stimulation groups, with five mice per group. Based on the largest improvement in the indexes of the electroacupuncture group in experiment 1, experiment 2 was conducted. The other 15 C57BL/6 female mice were randomly divided into the model, electroacupuncture, and electroacupuncture + ADM3100 groups, with five mice per group. In the sham operation group, the catheter was only placed in the vagina without balloon injection expansion, whereas vaginal dilation was used in the other groups to construct the SUI model. Experiment 1: the sham operation and the model groups received no intervention; the "Ciliao" (BL32) was stimulated in the electroacupuncture group; the acupuncture group was only acupunctured at "Ciliao" (BL32); and the electrode sheet was attached to the "Ciliao" (BL32) in the electrical stimulation group. Experiment 2: the model group received no intervention; the electroacupuncture+ADM3100 group received ADM3100 solution injected peritoneally 24 h before the first intervention, followed by electroacupuncture at "Ciliao" (BL32); and the electroacupuncture group received an equal volume of phosphate-buffered saline injected peritoneally 24 h before the first intervention, followed by electroacupuncture at "Ciliao" (BL32). Each intervention lasted 20 min, once daily for 7 consecutive days. After the intervention, the modified simulated human urethral bladder intubation method was used to record the bladder leakage point pressure (BLPP) and abdominal leakage point pressure (ALPP). Masson staining was used to detect collagen deposition in periurethral tissue. The content of mitochondrial adenosine triphosphate (ATP) in periurethral tissue was detected using a luciferase luminescence assay. Immunofluorescence staining was used to detect the homing of BMMSC in periurethral tissue. JC-1 staining method was used to detect mitochondrial membrane potential in periurethral tissue. The expression of reactive oxygen species (ROS) in periurethral tissue was detected using the fluorescent probe DCFH-DA method. Real-time PCR was used to detect the mRNA expression of stromal cell-derived factor-1α(SDF-1α) in periurethral tissue.

Experiment 1: compared with the sham operation group, the BLPP and ALPP of the mice in the model group decreased (P < 0.05); the blue staining of collagen fibers in the periurethral tissue was lighter, the distribution was disordered, and the deposition was reduced; the collagen volume fraction, mitochondrial membrane potential and mitochondrial ATP content in the periurethral tissue decreased, whereas the ROS expression increased (P < 0.05). Compared with the model group, BLPP and ALPP in the electroacupuncture, acupuncture, and electrical stimulation groups were increased (P < 0.05); the blue staining of collagen fibers in the periurethral tissue deepened, the distribution disorder was reduced, and the deposition increased; and the collagen volume fraction of the periurethral tissue, BMMSC ratio, mitochondrial membrane potential, mitochondrial ATP content, and the mRNA expression of SDF-1α increased, the ROS expression decreased (P < 0.05). Compared with the electroacupuncture group, BLPP and ALPP decreased in the acupuncture and electrical stimulation groups (P < 0.05); and the collagen volume fraction, BMMSC ratio, mitochondrial membrane potential, mitochondrial ATP content, and SDF-1α mRNA expression in periurethral tissue decreased, whereas ROS expression increased (P < 0.05). Experiment 2: compared with the electroacupuncture group, the BLPP and ALPP of mice in the electroacupuncture+ADM3100 group decreased (P < 0.05); and the collagen volume fraction of periurethral tissue, BMMSC ratio, mitochondrial membrane potential, mitochondrial ATP content, and SDF-1α mRNA expression decreased, whereas the ROS expression increased (P < 0.05).

Electroacupuncture at "Ciliao" (BL32) may improve mitochondrial homeostasis imbalance in periurethral tissues by promoting endogenous BMMSC homing in SUI mice, thereby improving SUI.