Pain in chronic prostatitis and the role of ion channels: a brief overview

Characterizing CD8+ TEMRA Cells in CP/CPPS Patients: Insights from Targeted Single-Cell Transcriptomic and Functional Investigations

Background

The specific involvement of the CD8+ T effector memory RA (TEMRA) subset in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has largely not been explored in the literature.

Methods

Targeted single-cell RNA sequencing (scRNA-seq) profiles were generated from peripheral blood mononuclear cells (PBMCs) obtained from two CP/CPPS patients and two healthy controls (HCs) in our recent study. Pseudotime series algorithms were used to reveal the differentiation trajectory, CellChat analysis was used to explore the communication between individual cells, and the SCENIC program was used to identify potential transcription factors (TFs). Based on the cosine similarity, clusters of differentially expressed genes (DEGs) were considered to be further enriched in different pathways. To confirm the functional role of the critical clusters, flow cytometry was employed.

Results

The results revealed the molecular landscape of these clusters, with TEMRA cells exhibiting pronounced cytokine-mediated signaling pathway enrichment. Pseudotime trajectory analysis further mapped the evolution from naïve T cells to that of TEMRA cells, elucidating the developmental pathways involved in the immune context. A significant finding from CellChat analysis was the differential expression of ligands and receptors, with CD8+ TEMRA cells showing enhanced signaling, particularly in the CP/CPPS context, compared to HCs. Flow cytometry confirmed these results, revealing a heightened proinflammatory cytokine profile in patients with chronic prostatitis-like symptoms (CP-LS), suggesting that TEMRA cells play a significant role in disease pathogenesis. TF profiling across the T-cell clusters identified key regulators of cellular identity, identifying novel therapeutic targets. Elevated TNF signaling activity in CD8+ TEMRA cells underscored the involvement of these cells in disease mechanisms.

Conclusion

This study elucidates the pivotal role of the CD8+ TEMRA cell subset in CP/CPPS, which is characterized by increased TNF signaling and proinflammatory factor expression, highlighting potential biomarkers and opening new avenues for therapeutic intervention.

Thermosensitive hydrogel with emodin-loaded triple-targeted nanoparticles for a rectal drug delivery system in the treatment of chronic non-bacterial prostatitis

BACKGROUND

The complex etiology and pathogenesis underlying Chronic Non-Bacterial Prostatitis (CNP), coupled with the existence of a Blood Prostate Barrier (BPB), contribute to a lack of specificity and poor penetration of most drugs. Emodin (EMO), a potential natural compound for CNP treatment, exhibits commendable anti-inflammatory, anti-oxidant, and anti-fibrosis properties but suffers from the same problems as other drugs.

METHODS

By exploiting the recognition properties of lactoferrin (LF) receptors that target intestinal epithelial cells (NCM-460) and prostate epithelial cells (RWPE-1), a pathway is established for the transrectal absorption of EMO to effectively reach the prostate. Additionally, hyaluronic acid (HA) is employed, recognizing CD44 receptors which target macrophages within the inflamed prostate. This interaction facilitates the intraprostatic delivery of EMO, leading to its pronounced anti-inflammatory effects. A thermosensitive hydrogel (CS-Gel) prepared from chitosan (CS) and β-glycerophosphate disodium salt (β-GP) was used for rectal drug delivery with strong adhesion to achieve effective drug retention and sustained slow release. Thus, we developed a triple-targeted nanoparticle (NPs)/thermosensitive hydrogel (Gel) rectal drug delivery system. In this process, LF, with its positive charge, was utilized to load EMO through dialysis, producing LF@EMO-NPs. Subsequently, HA was employed to encapsulate EMO-loaded LF nanoparticles via electrostatic adsorption, yielding HA/LF@EMO-NPs. Finally, HA/LF@EMO-NPs lyophilized powder was added to CS-Gel (HA/LF@EMO-NPs Gel).

RESULTS

Cellular assays indicated that NCM-460 and RWPE-1 cells showed high uptake of both LF@EMO-NPs and HA/LF@EMO-NPs, while Raw 264.7 cells exhibited substantial uptake of HA/LF@EMO-NPs. For LPS-induced Raw 264.7 cells, HA/LF@EMO-NPs can reduce the inflammatory responses by modulating TLR4/NF-κB signaling pathways. Tissue imaging corroborated the capacity of HA/LF-modified formulations to breach the BPB, accumulating within the gland's lumen. Animal experiments showed that rectal administration of HA/LF@EMO-NPs Gel significantly reduced inflammatory cytokine expression, oxidative stress levels and fibrosis in the CNP rats, in addition to exerting anti-inflammatory effects by inhibiting the NF-κB signaling pathway without obvious toxicity.

CONCLUSION

This triple-targeted NPs/Gel rectal delivery system with slow-release anti-inflammatory, anti-oxidant, and anti-fibrosis properties shows great potential for the effective treatment of CNP.

Glial Cells of the Central Nervous System: A Potential Target in Chronic Prostatitis/Chronic Pelvic Pain Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is one of the most common diseases of the male urological system while the etiology and treatment of CP/CPPS remain a thorny issue. Cumulative research suggested a potentially important role of glial cells in CP/CPPS. This narrative review retrospected literature and grasped the research process about glial cells and CP/CPPS. Three types of glial cells showed a crucial connection with general pain and psychosocial symptoms. Microglia might also be involved in lower urinary tract symptoms. Only microglia and astrocytes have been studied in the animal model of CP/CPPS. Activated microglia and reactive astrocytes were found to be involved in both pain and psychosocial symptoms of CP/CPPS. The possible mechanism might be to mediate the production of some inflammatory mediators and their interaction with neurons. Glial cells provide a new insight to understand the cause of complex symptoms of CP/CPPS and might become a novel target to develop new treatment options. However, the activation and action mechanism of glial cells in CP/CPPS needs to be further explored.

Chronic Prostatitis/Chronic Pain Pelvic Syndrome and Male Infertility

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is defined as urologic pain or discomfort in the pelvic region, associated with urinary symptoms and/or sexual dysfunction, lasting for at least 3 of the previous 6 months. The rate of symptoms related to prostatitis has a mean prevalence of 8-8.2%. CP/CPPS is most frequent in men younger than 50 years, among whom it is the most common urologic diagnosis. In the last decades, many studies have been published on CP/CPPS and its association with male infertility. The pathophysiologic relation between CP/CPPS and male infertility involves several aspects, which are not well studied yet. A reduction in semen parameters has been demonstrated in patients with CP/CPPS, and several mechanisms have been proposed to represent putative pathophysiological links between CP/CPPS and infertility, including male accessory gland inflammation, metabolic syndrome, inflammatory bowel disease, HPV co-infection and autoimmunity. In light of this evidence, a multidisciplinary approach is advocated for patients with known CP/CPPS, and particular attention is needed for male patients of infertile couples in order to evaluate male accessory glands correctly. In addition, it is advisable that future studies dealing with the treatment of CP/CPPS take into consideration all the different pathophysiological aspects implicated.

Acidosis-related pain and its receptors as targets for chronic pain

Sensing acidosis is an important somatosensory function in responses to ischemia, inflammation, and metabolic alteration. Accumulating evidence has shown that acidosis is an effective factor for pain induction and that many intractable chronic pain diseases are associated with acidosis signaling. Various receptors have been known to detect extracellular acidosis and all express in the somatosensory neurons, such as acid sensing ion channels (ASIC), transient receptor potential (TRP) channels and proton-sensing G-protein coupled receptors. In addition to sense noxious acidic stimulation, these proton-sensing receptors also play a vital role in pain processing. For example, ASICs and TRPs are involved in not only nociceptive activation but also anti-nociceptive effects as well as some other non-nociceptive pathways. Herein, we review recent progress in probing the roles of proton-sensing receptors in preclinical pain research and their clinical relevance. We also propose a new concept of sngception to address the specific somatosensory function of acid sensation. This review aims to connect these acid-sensing receptors with basic pain research and clinical pain diseases, thus helping with better understanding the acid-related pain pathogenesis and their potential therapeutic roles via the mechanism of acid-mediated antinociception.