Brain-Derived Neurotrophic Factor Is an Important Therapeutic Factor in Mesenchymal Stem Cell Secretions for Treatment of Traumatic Peripheral Pelvic Injuries

Brain-derived neurotrophic factor-based therapies in peripheral nerve injury-a systematic review of animal studies

Peripheral nerve injuries (PNIs) remain a significant clinical problem, producing permanent motor-sensory deficits and diminishing patient's quality of life. Neurotrophic growth factors, a family of biomolecules, support neuronal survival and regeneration. Among them, Brain-Derived Neurotrophic Factor (BDNF) emerged as a key modulator of neurogenesis and neuroregeneration within the peripheral nervous system. This systematic review evaluates and summarises animal-based evidence on BDNF-based therapies used in peripheral nerve injury (PNI). A literature search in PubMed, EMBASE, Scopus, and Web of Science with the latest results from 10th of October 2024 to identify animal-based studies evaluating the effects of BDNF-based therapies used in PNI. Of 785 records, 40 articles met the inclusion criteria, encompassing 1887 rats and 430 mice or rabbits across various injury models. Gathered studies heterogenicity precluded meta-analysis, but most reports showed superior axonal regeneration, myelination, and functional recovery in BDNF-based therapies compared to control groups. The benefits were most significant with multimodal strategies, including multiple neurotrophins and stem cells. Combined therapies involving multiple neurotrophic growth factors, BDNF, and stem cell therapies showed the most significant improvement in functional outcomes and histological parameters of injured nerves. These results suggest that BDNF-based therapies hold promise for effective PNI treatment. GLOSSARY.

The Risk Factors of Postpartum Urinary Retention for Women by Vaginal Birth: A Systematic Review and Meta-Analysis

INTRODUCTION AND HYPOTHESIS

Postpartum urinary retention is one of the most common complications in women during the immediate postpartum period. The objective was to systematically assess risk factors for postpartum urinary retention after vaginal delivery.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we retrieved relevant studies from PubMed, Embase, Cochrane Library, Web of Science Core Collection, China National Knowledge Internet, Wangfang Database, and Chinese Biomedical Database for observational studies investigating the risk factors for postpartum urinary retention from inception to 11 November 2022. The Newcastle-Ottawa Scale and Joanna Briggs Institute's tool were used to assess the risk of bias. We conducted a meta-analysis using RevMan 5.3.

RESULTS

In total, 3,074 articles were screened and data from 27 studies were used in the meta-analysis. Sixteen risk factors were identified, namely, labor augmentation (OR = 1.72, 95% CI = 1.17-2.51), primiparity (OR = 2.36, 95% CI = 1.64-3.38), manual fundal pressure (OR = 2.84, 95% CI = 1.00-8.11), perineal hematoma (OR = 7.28, 95% CI = 1.62-32.72), vulvar edema (OR = 7.99, 95% CI = 5.50-11.63), the total duration of labor (MD = 90.10, 95% CI = 49.11-131.08), the duration of the first stage of labor (MD = 33.97, 95% CI = 10.28-57.65), the duration of the second stage of labor (MD = 14.92, 95% CI = 11.79-18.05), the duration of the second stage of labor > 60 min (OR = 3.18, 95% CI = 1.32-7.67), mediolateral episiotomy (OR = 3.65, 95% CI = 1.70-7.83), severe perineal tear (OR = 3.21, 95% CI = 1.84-5.61), epidural analgesia (OR = 3.23, 95% CI = 1.50-6.96), forceps delivery (OR = 4.95, 95% CI = 2.88-8.51), vacuum delivery (OR = 2.44, 95% CI = 1.30-4.58), neonatal birth weight > 4,000 g (OR = 3.61, 95% CI = 1.96-6.65), and neonatal birth weight > 3,500 g (OR = 1.89, 95% CI = 1.12-3.19).

CONCLUSIONS

Our results demonstrated that labor augmentation, primiparity, manual fundal pressure, perineal hematoma, vulvar edema, the total duration of labor, the duration of the first stage of labor, the duration of the second stage of labor, the duration of the second stage of labor > 60 min, mediolateral episiotomy, severe perineal tear, epidural analgesia, forceps delivery, vacuum delivery, and neonatal birth weight > 4,000 g and > 3,500 g were risk factors for postpartum urinary retention in women with vaginal delivery. The specific ranges of the first and the second stages of labor causing postpartum urinary retention need to be clarified.

Cellular regenerative therapy in stress urinary incontinence: new frontiers?-a narrative review

Background and Objective

Even if treatment with stem cells has been shown to be safe and effective in many patients with stress urinary incontinence (SUI), there is still room for improvement using other regenerative medicine alternatives. Since the beneficial effects of stem cells are probably mediated by secretion of factors rather than by the cells themselves there is a good rationale for further exploring the therapeutic effects of the secretome and/or its components. However, homing factors such as stromal derived growth factor 1 (SDF-1; CXCL12), stimulation of stem cell growth and stem cell mobilization in vivo using low intensity shock wave therapy (Li-ESWT) or regenerative electrical stimulation (RES), are also promising approaches.

Methods

A literature search was performed based on PubMed, Scopus and Google Scholar. The search criteria included original basic science articles, systematic reviews and randomized control trials. All studies were published between 2000 and 2023. Selected, peer-reviewed studies were further analyzed to identify those of relevance. Keywords searched included: "female stress incontinence", "homing factors", "CXCL12", "secretome", "low intensity shockwave therapy" and "regenerative electrical stimulation". The peer-reviewed publications on the key word subjects that contained a novel addition to the existing body of literature were included.

Key Content and Findings

There is evidence from studies on non-human primates (NHPs) with experimental urinary sphincter injury that CXCL12 can restore sphincter structure and function. Studies with homing factors in human patients with SUI are still to be performed. A large number of clinical studies on the use of secretome or secretome products from mesenchymal stem cells (MSCs) on indications other than human SUI are already available. However, controlled clinical trials on patients with SUI, have to the best of our knowledge, not yet been performed. Also, RES has not been studied in patients with SUI. In contrast, there is clinical evidence that Li-ESWT may improve female SUI.

Conclusions

Treatment with homing factors, MSC secretome/secretome components, Li-ESWT and RES are promising frontiers in the treatment of human SUI caused by sphincter damage.

Mesenchymal stem cells: Guardians of women's health

Mesenchymal stem cells (MSCs) have attracted more and more attention because of their multidirectional differentiation potential, immune regulatory abilities and self-renewal capacity. In recent years, their use has become prominent in the domains of regenerative medicine and tissue engineering. MSCs have shown promise in therapeutic studies for a variety of diseases and have become a new source of innovative solutions for the treatment of some obstetric and gynecological diseases. This review systematically presents the latest research on the use of MSCs in the treatment of obstetrics- and gynecology-related diseases. Specifically, this review encompasses the latest findings related to the role of MSCs in premature ovarian failure, polycystic ovary syndrome, ovarian cancer, fallopian tube-related diseases, uterine adhesions, endometriosis, cesarean scar defects, postmenopausal osteoporosis, and pelvic floor dysfunction. The shortcomings and challenges of the future use of MSCs in disease treatment are also discussed, with the intent to motivate improvements in MSC applications in clinical therapy. It is believed that with further research, MSCs will play a more important role in the treatment of obstetrics- and gynecology-related diseases.

Multipotent bone marrow cell-seeded polymeric composites drive long-term, definitive urinary bladder tissue regeneration

To date, there are no efficacious translational solutions for end-stage urinary bladder dysfunction. Current surgical strategies, including urinary diversion and bladder augmentation enterocystoplasty (BAE), utilize autologous intestinal segments (e.g. ileum) to increase bladder capacity to protect renal function. Considered the standard of care, BAE is fraught with numerous short- and long-term clinical complications. Previous clinical trials employing tissue engineering approaches for bladder tissue regeneration have also been unable to translate bench-top findings into clinical practice. Major obstacles still persist that need to be overcome in order to advance tissue-engineered products into the clinical arena. These include scaffold/bladder incongruencies, the acquisition and utility of appropriate cells for anatomic and physiologic tissue recapitulation, and the choice of an appropriate animal model for testing. In this study, we demonstrate that the elastomeric, bladder biomechanocompatible poly(1,8-octamethylene-citrate-co-octanol) (PRS; synthetic) scaffold coseeded with autologous bone marrow-derived mesenchymal stem cells and CD34+ hematopoietic stem/progenitor cells support robust long-term, functional bladder tissue regeneration within the context of a clinically relevant baboon bladder augmentation model simulating bladder trauma. Partially cystectomized baboons were independently augmented with either autologous ileum or stem-cell-seeded small-intestinal submucosa (SIS; a commercially available biological scaffold) or PRS grafts. Stem-cell synergism promoted functional trilayer bladder tissue regeneration, including whole-graft neurovascularization, in both cell-seeded grafts. However, PRS-augmented animals demonstrated fewer clinical complications and more advantageous tissue characterization metrics compared to ileum and SIS-augmented animals. Two-year study data demonstrate that PRS/stem-cell-seeded grafts drive bladder tissue regeneration and are a suitable alternative to BAE.

Neurobiological insights into lower urinary tract dysfunction: evaluating the role of brain-derived neurotrophic factor

Lower urinary tract dysfunction (LUTD) encompasses a range of debilitating conditions that affect both sexes and different age groups. Understanding the underlying neurobiological mechanisms contributing to LUTD has emerged as a critical avenue for the development of targeted therapeutic strategies. Brain-derived neurotrophic factor (BDNF), a prominent member of the neurotrophin family, has attracted attention due to its multiple roles in neural development, plasticity, and maintenance. This review examines the intricate interplay between neurobiological factors and LUTD, focusing on the central involvement of BDNF. The review emphasizes the bidirectional relationship between LUTD and BDNF and explores how LUTD-induced neural changes may affect BDNF dynamics and vice versa. Growth factor therapy and the combined administration of controlled release growth factors and stem cells are minimally invasive treatment strategies for neuromuscular injury. Among the many growth factors and cytokines, brain-derived neurotrophic factor (BDNF) plays a prominent role in neuromuscular repair. As an essential neurotrophin, BDNF is involved in the modulation of neuromuscular regeneration through tropomyosin receptor kinase B (TrkB). Increasing BDNF levels facilitates the regeneration of the external urethral sphincter and contributes to the regulation of bladder contraction. Treatments targeting the BDNF pathway and sustained release of BDNF may become novel treatment options for urinary incontinence and other forms of lower urinary tract dysfunction. This review discusses the applications of BDNF and the theoretical basis for its use in the treatment of lower urinary tract dysfunction, including urinary incontinence (UI), overactive bladder (OAB), and benign prostatic hyperplasia (BPH), and in the clinical diagnosis of bladder dysfunction.

T12-L3 Nerve Transfer-Induced Locomotor Recovery in Rats with Thoracolumbar Contusion: Essential Roles of Sensory Input Rerouting and Central Neuroplasticity

Locomotor recovery after spinal cord injury (SCI) remains an unmet challenge. Nerve transfer (NT), the connection of a functional/expendable peripheral nerve to a paralyzed nerve root, has long been clinically applied, aiming to restore motor control. However, outcomes have been inconsistent, suggesting that NT-induced neurological reinstatement may require activation of mechanisms beyond motor axon reinnervation (our hypothesis). We previously reported that to enhance rat locomotion following T13-L1 hemisection, T12-L3 NT must be performed within timeframes optimal for sensory nerve regrowth. Here, T12-L3 NT was performed for adult female rats with subacute (7-9 days) or chronic (8 weeks) mild (SCImi: 10 g × 12.5 mm) or moderate (SCImo: 10 g × 25 mm) T13-L1 thoracolumbar contusion. For chronic injuries, T11-12 implantation of adult hMSCs (1-week before NT), post-NT intramuscular delivery of FGF2, and environmentally enriched/enlarged (EEE) housing were provided. NT, not control procedures, qualitatively improved locomotion in both SCImi groups and animals with subacute SCImo. However, delayed NT did not produce neurological scale upgrading conversion for SCImo rats. Ablation of the T12 ventral/motor or dorsal/sensory root determined that the T12-L3 sensory input played a key role in hindlimb reanimation. Pharmacological, electrophysiological, and trans-synaptic tracing assays revealed that NT strengthened integrity of the propriospinal network, serotonergic neuromodulation, and the neuromuscular junction. Besides key outcomes of thoracolumbar contusion modeling, the data provides the first evidence that mixed NT-induced locomotor efficacy may rely pivotally on sensory rerouting and pro-repair neuroplasticity to reactivate neurocircuits/central pattern generators. The finding describes a novel neurobiology mechanism underlying NT, which can be targeted for development of innovative neurotization therapies.

Brain-Derived Neurotrophic Factor Is Indispensable to Continence Recovery after a Dual Nerve and Muscle Childbirth Injury Model

In women, stress urinary incontinence (SUI), leakage of urine from increased abdominal pressure, is correlated with pudendal nerve (PN) injury during childbirth. Expression of brain-derived neurotrophic factor (BDNF) is dysregulated in a dual nerve and muscle injury model of childbirth. We aimed to use tyrosine kinase B (TrkB), the receptor of BDNF, to bind free BDNF and inhibit spontaneous regeneration in a rat model of SUI. We hypothesized that BDNF is essential for functional recovery from the dual nerve and muscle injuries that can lead to SUI. Female Sprague-Dawley rats underwent PN crush (PNC) and vaginal distension (VD) and were implanted with osmotic pumps containing saline (Injury) or TrkB (Injury + TrkB). Sham Injury rats received sham PNC + VD. Six weeks after injury, animals underwent leak-point-pressure (LPP) testing with simultaneous external urethral sphincter (EUS) electromyography recording. The urethra was dissected for histology and immunofluorescence. LPP after injury and TrkB was significantly decreased compared to Injury rats. TrkB treatment inhibited reinnervation of neuromuscular junctions in the EUS and promoted atrophy of the EUS. These results demonstrate that BDNF is essential to neuroregeneration and reinnervation of the EUS. Treatments aimed at increasing BDNF periurethrally could promote neuroregeneration to treat SUI.