A Novel Intravesical Dextrose Injection Improves Lower Urinary Tract Symptoms on Interstitial Cystitis/Bladder Pain Syndrome

Therapeutic Effects of AF219 on Interstitial Cystitis/Bladder Pain Syndrome Induced by Cyclophosphamide or Water Avoidance Stress in Rats

INTRODUCTION AND HYPOTHESIS

To evaluate the effect of AF219, a P2X3 receptor antagonist, in animal models of interstitial cystitis/bladder pain syndrome (IC/BPS) induced by cyclophosphamide (CYP) or water avoidance stress (WAS).

METHODS

Thirty-two adult female Wistar albino rats were used in each IC/BPS model. Assessment of nociception and anxiety and severity of inflammation in the bladder were assessed by behavioral experiments and histopathological examinations respectively. The contraction responses of the bladder were evaluated in vitro and protein levels of P2X3, P2X7, Trk-A, TRPV1, and TRPA1 were analyzed by Western blot.

RESULTS

The IC/BPS groups had shorter response times to noxious stimuli, exhibited more anxiety-like behavior, had higher inflammation-based histological scores, and showed greater increased contraction responses to carbachol, adenosine triphosphate, and electrical field stimulation in in vitro bladder strips than controls for both models (p < 0.05). The improvements in behavioral and bladder contraction responses and inflammation scores in the IC/BPS + AF219 groups were similar to control findings (p > 0.05). Exposure to WAS or CYP increased P2X3 expression in the bladder compared with the controls (p < 0.05). Apart from TRPA1, the levels of P2X7, Trk-A, and TRPV1 were also higher in the IC/BPS groups than in the controls (p < 0.05). No significant differences were observed between IC/BPS + AF219 and controls regarding P2X3, P2X7, Trk-A, and TRPV1 in the WAS model (p > 0.05). Moreover, P2X3 and P2X7 levels were significantly lower in IC/BPS + AF219 than in the AF219-untreated WAS model (p < 0.05).

CONCLUSIONS

These findings suggest that P2X3 receptors play a significant role in bladder functional responses, nociception, and also the pathogenesis of IC/BPS. AF219 may be a promising therapeutic strategy for IC/BPS. Comparing AF219 with current IC/BPS treatment agents in future studies may yield valuable insights into its efficacy.

Crosslinking chitosan with glucose via the modified Maillard reaction promotes the osteoinduction of mouse MC3T3-E1 pre-osteoblasts

Bone defects are a common clinical issue, but therapeutic efficiency can be challenging in cases of more considerable traumas or elderly patients with degenerated physiological metabolism. To address this issue, a more suitable cell-biomaterial construct promoting bone regeneration has been extensively investigated, with the chitosan scaffold being considered a potential candidate. In this study, chitosan was crosslinked with different doses of glucose (CTS-10~50%Glc) using a modified Maillard reaction condition to develop a more appropriate cell-biomaterial construct. Mouse MC3T3-E1 pre-osteoblasts were seeded onto the scaffolds to examine their osteoinductive capability. The results showed that CTS-Glc scaffolds with higher glucose contents effectively improved the adhesion and survival of mouse MC3T3-E1 pre-osteoblasts and promoted their differentiation and mineralization. It was further demonstrated that the membrane integrin α5 subunit of pre-osteoblasts is the primary adhesion molecule that communicates with CTS-Glc scaffolds. After that, Akt signaling was activated, and then bone morphogenetic protein 4 was secreted to initiate the osteoinduction of pre-osteoblasts. The prepared CTS-Glc scaffold, with enhanced osteoinduction capability and detailed mechanism elucidations, offers a promising candidate material for advancing bone tissue engineering and clinical regenerative medicine. As a result, this study presents a potential tool for future clinical treatment of bone defects.

Molecular Profiling of Inflammatory Processes in a Mouse Model of IC/BPS: From the Complete Transcriptome to Major Sex-Related Histological Features of the Urinary Bladder

Animal models are invaluable in the research of the pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic aseptic urinary bladder disease of unknown etiology that primarily affects women. Here, a mouse model of IC/BPS was induced with multiple low-dose cyclophosphamide (CYP) applications and thoroughly characterized by RNA sequencing, qPCR, Western blot, and immunolabeling to elucidate key inflammatory processes and sex-dependent differences in the bladder inflammatory response. CYP treatment resulted in the upregulation of inflammatory transcripts such as Ccl8, Eda2r, and Vegfd, which are predominantly involved in innate immunity pathways, recapitulating the crucial findings in the bladder transcriptome of IC/BPS patients. The JAK/STAT signaling pathway was analyzed in detail, and the JAK3/STAT3 interaction was found to be most activated in cells of the bladder urothelium and lamina propria. Sex-based data analysis revealed that cell proliferation was more pronounced in male bladders, while innate immunity and tissue remodeling processes were the most distinctive responses of female bladders to CYP treatment. These processes were also reflected in prominent histological changes in the bladder. The study provides an invaluable reference dataset for preclinical research on IC/BPS and an insight into the sex-specific mechanisms involved in the development of IC/BPS pathology, which may explain the more frequent occurrence of this disease in women.

Mechanism of Glucose Water as a Neural Injection: A Perspective on Neuroinflammation

The entrapment of peripheral nerves is associated with chronic neuroinflammation and neuropathic pain, and perineural injection therapy with glucose is emerging as an effective treatment for peripheral entrapment neuropathy. However, the mechanism underlying the pharmacological effect of glucose on nerves remains unclear. One of the hypothesized mechanisms is that glucose reduces neurogenic inflammation. Therefore, we investigated the effects of high glucose concentrations on cytokine-induced neuroinflammation in vitro. Human SH-SY5Y neuronal cells were challenged with 10 ng/mL TNF-α for 16 h and subsequently treated with different glucose concentrations (0–25 mM) for 24 h. Cell viability was evaluated using the diphenyltetrazolium bromide assay, and proinflammatory cytokine levels were assessed using ELISA and quantitative PCR. In addition, mRNA levels of NF-κB and cyclooxygenase-2 were analyzed using quantitative PCR. Exposure to 10 ng/mL TNF-α resulted in decreased viability of SH-SY5Y cells and significant upregulation of IL-6, IL-1β, NF-κB, and cyclooxygenase-2. Subsequent exposure to high glucose levels (25 mM) markedly reduced the upregulation of IL-6, IL-1β, cyclooxygenase-2, and NF-κB, and restored the functional metabolism of SH-SY5Y cells, compared with that of the normal glucose control. Our findings suggest that high glucose concentrations can mitigate TNF-α-induced NF-κB activation, upregulation of proinflammatory cytokines, and metabolic dysfunction.