Injecting RNA interference lentiviruses targeting the muscarinic 3 receptor gene into the bladder wall inhibits neurogenic detrusor overactivity in rats with spinal cord injury

Development of a Dynamic Nomogram for Predicting the Probability of Satisfactory Recovery after 6 Months for Cervical Traumatic Spinal Cord Injury

OBJECTIVE

Cervical traumatic spinal cord injury (CTSCI) is a seriously disabling disease that severely affects the physical and mental health of patients and imposes a huge economic burden on patients and their families. Accurate identification of the prognosis of CTSCI patients helps clinicians to design individualized treatment plans for patients. For this purpose, a dynamic nomogram was developed to predict the recovery of CTSCI patients after 6 months.

METHODS

We retrospectively included 475 patients with CTSCI in our institution between March 2013 and January 2022. The outcome variable of the current study was a satisfactory recovery of patients with CTSCI at 6 months. Univariate analyses and univariate logistic regression analyses were used to assess the factors affecting the prognosis of patients with CTSCI. Subsequently, variables (P < 0.05) were included in the multivariate logistic regression analysis to evaluate these factors further. Eventually, a nomogram model was constructed according to these independent risk factors. The concordance index (C-index) and the calibration curve were utilized to assess the model's predictive ability. The discriminating capacity of the prediction model was measured by the receiver operating characteristic (ROC) area under the curve (AUC). One hundred nine patients were randomly selected from 475 patients to serve as the center's internal validation test cohort.

RESULTS

The multivariate logistic regression model further screened out six independent factors that impact the recovery of patients with CTSCI. Including admission to the American Spinal Injury Association Impairment Scale (AIS) grade, the length of high signal in the spinal cord, maximum spinal cord compression (MSCC), spinal segment fractured, admission time, and hormonal therapy within 8 h after injury. A nomogram prediction model was developed based on the six independent factors above. In the training cohort, the AUC of the nomogram that included these predictors was 0.879, while in the test cohort, it was 0.824. The nomogram C-index incorporating these predictors was 0.872 in the training cohort and 0.813 in the test cohort, while the calibration curves for both cohorts also indicated good consistency. Furthermore, this nomogram was converted into a Web-based calculator, which provided individual probabilities of recovery to be generated for individuals with CTSCI after 6 months and displayed in a graphical format.

CONCLUSION

The nomogram, including ASIA grade, the length of high signal in the spinal cord, MSCC, spinal segment fractured, admission time, and hormonal therapy within 8 h after injury, is a promising model to predict the probability of content recovery in patients with CTSCI. This nomogram assists clinicians in stratifying patients with CTSCI, enhancing evidence-based decision-making, and individualizing the most appropriate treatment.

Molecular Mechanism Operating in Animal Models of Neurogenic Detrusor Overactivity: A Systematic Review Focusing on Bladder Dysfunction of Neurogenic Origin

Neurogenic detrusor overactivity (NDO) is a severe lower urinary tract disorder, characterized by urinary urgency, retention, and incontinence, as a result of a neurologic lesion that results in damage in neuronal pathways controlling micturition. The purpose of this review is to provide a comprehensive framework of the currently used animal models for the investigation of this disorder, focusing on the molecular mechanisms of NDO. An electronic search was performed with PubMed and Scopus for literature describing animal models of NDO used in the last 10 years. The search retrieved 648 articles, of which reviews and non-original articles were excluded. After careful selection, 51 studies were included for analysis. Spinal cord injury (SCI) was the most frequently used model to study NDO, followed by animal models of neurodegenerative disorders, meningomyelocele, and stroke. Rats were the most commonly used animal, particularly females. Most studies evaluated bladder function through urodynamic methods, with awake cystometry being particularly preferred. Several molecular mechanisms have been identified, including changes in inflammatory processes, regulation of cell survival, and neuronal receptors. In the NDO bladder, inflammatory markers, apoptosis-related factors, and ischemia- and fibrosis-related molecules were found to be upregulated. Purinergic, cholinergic, and adrenergic receptors were downregulated, as most neuronal markers. In neuronal tissue, neurotrophic factors, apoptosis-related factors, and ischemia-associated molecules are increased, as well as markers of microglial and astrocytes at lesion sites. Animal models of NDO have been crucial for understanding the pathophysiology of lower urinary tract (LUT) dysfunction. Despite the heterogeneity of animal models for NDO onset, most studies rely on traumatic SCI models rather than other NDO-driven pathologies, which may result in some issues when translating pre-clinical observations to clinical settings other than SCI.

Schwann cell-derived exosomes containing MFG-E8 modify macrophage/microglial polarization for attenuating inflammation via the SOCS3/STAT3 pathway after spinal cord injury

Macrophage/microglia polarization acts as an important part in regulating inflammatory responses in spinal cord injury (SCI). However, the regulation of inflammation of Schwann cell-derived exosomes (SCDEs) for SCI repair is still unclear. Therefore, we intend to find out the effect of SCDEs on regulating the inflammation related to macrophage polarization during the recovery of SCI. Firstly, the thesis demonstrated that SCDEs could attenuate the LPS- inflammation in BMDMs by suppressing M1 polarization and stimulating M2 polarization. Similarly, SCDEs improved functional recovery of female Wistar rats of the SCI contusion model according to BBB (Basso, Beattie, and Bresnahan) score, electrophysiological assay, and the gait analysis system of CatWalk XT. Moreover, MFG-E8 was verified as the main component of SCDEs to improve the inflammatory response by proteomic sequencing and lentiviral transfection. Improvement of the inflammatory microenvironment also inhibited neuronal apoptosis. The knockout of MFG-E8 in SCs can reverse the anti-inflammatory effects of SCDEs treatment. The SOCS3/STAT3 signaling pathway was identified to participate in upregulating M2 polarization induced by MFG-E8. In conclusion, our findings will enrich the mechanism of SCDEs in repairing SCI and provide potential applications and new insights for the clinical translation of SCDEs treatment for SCI.

Outcomes of Patients with Cervical Spinal Cord Injury Treated by Surgery and Their Prognostic Factors

Objective

To investigate the outcomes of patients with cervical spinal cord injury treated by surgery and their prognostic factors.

Methods

We retrospectively analyzed 139 patients with cervical spinal cord injury treated by surgery at our hospital, who were admitted between January 2017 and December 2018. Depending on the Barthel index at last follow-up, the patients were divided into the recovery group (n = 60, Barthel index > 45) and the nonrecovery group (n = 79, Barthel index ≤ 45). General information of patients in the two groups was compared. The significant factors were further introduced into the logistic regression model. The poor prognostic factors of cervical spinal cord injury treated by surgery were analyzed, and specific nursing measures were taken.

Results

There were significant differences in the duration of injury before admission, duration of injury before surgery, transportation and protection before admission, spinal canal invasion rate, and hormonal therapy within 8 h after injury between the patients achieving good postoperative recovery and those not (P < 0.05). Logistic regression analysis showed that all the factors above were prognostic factors for cervical spinal cord injury treated surgically.

Conclusion

The duration of injury before admission, duration of injury before surgery, transportation and protection before admission, spinal canal invasion rate, and hormonal therapy within 8 h after injury were prognostic factors of patients with cervical spinal cord injury treated by surgery. The following factors should be considered for favorable outcomes: spinal protection during transportation to hospital, timely hormonal shock therapy to delay injury progression, and timely surgery to relieve pain. The spine is composed of cervical, thoracic, lumbar, sacral, and caudal vertebrae.

Telmisartan inhibits bladder smooth muscle fibrosis in neurogenic bladder rats

Hypertension is associated with bladder symptoms. The present study investigated whether an angiotensin receptor blocker could improve the symptoms and pathological changes associated with a neurogenic bladder (NB). A Sprague-Dawley rat model of NB was constructed. Rats in the sham and model groups were gavaged with saline, and rats in the treatment group were gavaged with telmisartan. Urodynamic parameters, including maximum cystometric capacity, residual urine volume, bladder wet weight, bladder compliance and detrusor pressure, were detected. Masson and H&E staining were performed to assess bladder fibrosis and histopathological changes. The expression levels of basic fibroblast growth factor (bFGF), TGF-β1, Collagen I, Collagen III, and α-smooth muscle actin (α-SMA) were also measured by reverse transcription-quantitative PCR, western blotting and immunohistochemistry. The model rats exhibited symptoms and pathological changes associated with NB. Treatment with telmisartan reduced maximum cystometric capacity, residual urine volume, bladder compliance and bladder wet weight, and increased detrusor pressure in model rats. The tissue staining results showed that telmisartan exerted an antifibrotic effect. In addition, telmisartan inhibited the expression of bFGF, TGF-β1, Collagen I, Collagen III and α-SMA in model rats. Therefore, the results of the present study indicated that telmisartan may serve as a potential therapeutic agent for NB.

Antifibrosis treatment by inhibition of VEGF, FGF, and PDGF receptors improves bladder wall remodeling and detrusor overactivity in association with modulation of C-fiber afferent activity in mice with spinal cord injury

AIMS

Spinal cord injury (SCI) above the sacral level causes bladder dysfunction and remodeling with fibrosis. This study examined the antifibrotic effects using nintedanib, an inhibitor of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor receptors, on detrusor overactivity (DO) and bladder fibrosis, as well as the modulation mechanisms of C-fiber afferent pathways.

METHODS

Thirty female C57BL/6 mice were divided into group A (spinal intact), group B (SCI with vehicle), and group C (SCI with nintedanib). At 2 weeks after SCI, vehicle or 50 mg/kg nintedanib was administered subcutaneously for 2 weeks. Then, cystometry was conducted, followed by RT-PCR measurements of fibrosis-related molecules, muscarinic, β-adrenergic, TRP and purinergic receptors in the bladder or L6-S1 dorsal root ganglia (DRG). Trichrome stain and Western blot analysis of transforming growth factor-beta and fibronectin were performed in the bladder. TRPV1 expression in L6 DRG was measured by immunohistochemistry.

RESULTS

In cystometry, intercontraction intervals, nonvoiding contractions, voided volume, and voiding efficiency were significantly improved in group C versus group B. RT-PCR, Western blotting, and trichrome staining revealed the fibrotic changes in the bladder of group B, which was improved in group C. Increased messenger RNA levels of TRPV1, TRPA1, P2X₂ , and P2X₃ in DRG of group B were significantly decreased in group C. TRPV1 immunoreactivity in DRG was increased in group B, but decreased in group C.

CONCLUSIONS

Nintedanib improves storage and voiding dysfunctions and bladder fibrosis in SCI mice. Also, nintedanib-induced improvement of DO is associated with reduced expression of C-fiber afferent markers, suggesting the modulation of bladder C-fiber afferent activity.

MicroRNA expression profile in the spinal cord injured rat neurogenic bladder by next-generation sequencing

Background

An increasing amount of evidence has indicated that microRNAs (miRs) are involved in most biological conditions, including the neurogenic bladder (NB). However, to our knowledge, no studies have investigated these miR expressions in spinal cord-injured (SCI) rat NB. The goal of the study was to explore the miR expression profile in the SCI rat NB by next-generation sequencing (NGS).

Methods

Female Wistar rats underwent spinal cord transection at T9–10 and were randomly divided into the SCI-1, SCI-2 and SCI-3 groups (n=5 for each group) whose bladder tissues were collected 1, 2, and 4 weeks after transection, respectively. The normal rats were used as the normal control (NC) group. MiRs microarray assays were used to detect the differentially expressed miRs between the groups by NGS, which was then verified by quantitative real-time polymerase chain reaction (qRT-PCR). Those significantly differently expressed miRs were analyzed with Gene Ontology categories and Kyoto Encyclopedia of Genes and Genomes bioinformatical analyses.

Results

Compared with the NC group, 96, 28 and 51 miRs were downregulated in the rats’ bladder in the SCI-1, SCI-2, and SCI-3 groups, respectively, and 133, 49, and 76 miRs were upregulated respectively. Specifically, miR-21-5p was the most significantly upregulated miR in all SCI groups. Also, 121 miRs (SCI-1 vs. SCI-2), 98 miRs (SCI-1 vs. SCI-3), and 26 miRs (SCI-2 vs. SCI-3) were of significantly different expression. Furthermore, a large set of genes implicated in essential signaling pathways were targeted by these miRs, including PI3K-Akt, MAPK, Rap1, and cGMP-PKG signaling pathways, along with the tight junction and metabolic pathways.

Conclusions

This is the first demonstration of differentially expressed miRs, which may potentially serve as new molecular targets in the SCI rat NB.