Appearance of High Endothelial Venule-Like Vessels in Benign Prostatic Hyperplasia is Associated With Lower Urinary tract Symptoms

Effects of oral administration of nonselective Trk inhibitor on bladder overactivity in rodent models of prostatic inflammation

BACKGROUND

Our research focused on the assessment of the impact of systemic inhibition of Trk receptors, which bind to nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), on bladder hypersensitivity in two distinct rodent models of prostatic inflammation (PI).

METHODS

Male Sprague-Dawley rats were divided into three groups (n = 6 each): the control group (no PI, vehicle administration), the untreated group (PI, vehicle administration), and the treated group (PI, nonselective Trk inhibitor, GNF 5837, administration). PI in rats was induced by a intraprostatic injection of 5% formalin. Posttreatment, we carried out conscious cystometry and a range of histological and molecular analyses. Moreover, the study additionally evaluated the effects of a nonselective Trk inhibitor on bladder overactivity in a mouse model of PI, which was induced by prostate epithelium-specific conditional deletion of E-cadherin.

RESULTS

The rat model of PI showed upregulations of NGF and BDNF in both bladder and prostate tissues in association with bladder overactivity and inflammation in the ventral lobes of the prostate. GNF 5837 treatment effectively mitigated these PI-induced changes, along with reductions in TrkA, TrkB, TrkC, and TRPV1 mRNA expressions in L6-S1 dorsal root ganglia. Also, in the mouse PI model, GNF 5837 treatment similarly improved bladder overactivity.

CONCLUSIONS

The findings of our study suggest that Trk receptor inhibition, which reduced bladder hypersensitivity and inflammatory responses in the prostate, along with a decrease in overexpression of Trk and TRPV1 receptors in sensory pathways, could be an effective treatment strategy for male lower urinary tract symptoms associated with PI and bladder overactivity.

Chronic inflammation in benign prostatic hyperplasia: Pathophysiology and treatment options

Benign prostatic hyperplasia, a prevalent condition in aging men, is characterized by the proliferation of prostatic epithelial and stromal cells, which leads to bladder outlet obstruction and the exacerbation of lower urinary tract symptoms. There is increasing evidence that chronic prostatic inflammation contributes to the pathogenesis and progression of benign prostatic hyperplasia. This review explores the complex relationship between chronic inflammation and benign prostatic hyperplasia, focusing on the underlying mechanisms, clinical implications, and current therapeutic approaches. The pathophysiology of benign prostatic hyperplasia is multifaceted, involving factors such as hormonal changes, hypoxia, urine reflux into prostatic ducts and stroma, autoimmune responses, and infection-induced inflammation. Inflammatory cytokines, particularly interleukin-17 and interleukin-8, may play key roles in tissue remodeling and smooth muscle contraction within the prostate, thereby influencing benign prostatic hyperplasia progression. Current therapies for benign prostatic hyperplasia include α1-blockers, phosphodiesterase 5 inhibitors, 5α-reductase inhibitors, and plant-based treatments (e.g., pollen extract). These therapies aim to alleviate symptoms by reducing prostatic inflammation, improving blood flow, and inhibiting hormonal pathways involved in prostatic enlargement. However, patients with chronic prostatic inflammation often experience more severe lower urinary tract symptoms and may be resistant to conventional treatments. This resistance has prompted the exploration of alternative therapies targeting inflammation. Chronic prostatic inflammation plays a central role in the pathogenesis and severity of benign prostatic hyperplasia. An understanding of its mechanisms will enable the development of more effective treatments to improve the quality of life among patients with benign prostatic hyperplasia.

PNAd-expressing vessels characterize the dermis of CD3+ T-cell-mediated cutaneous diseases

T-cell recruitment to skin tissues is essential for inflammation in different cutaneous diseases; however, the mechanisms by which these T cells access the skin remain unclear. High endothelial venules expressing peripheral node address in (PNAd), an L-selectin ligand, are located in secondary lymphoid organs and are responsible for increasing T-cell influx into the lymphoid tissues. They are also found in non-lymphoid tissues during inflammation. However, their presence in different common inflammatory cutaneous diseases and their correlation with T-cell infiltration remain unclear. Herein, we explored the mechanisms underlying the access of T cells to the skin by investigating the presence of PNAd-expressing vessels in different cutaneous diseases, and its correlation with T cells' presence. Skin sections of 43 patients with different diseases were subjected to immunohistochemical and immunofluorescence staining to examine the presence of PNAd-expressing vessels in the dermis. The correlation of the percentage of these vessels in the dermis of these patients with the severity/grade of CD3+ T-cell infiltration was assessed. PNAd-expressing vessels were commonly found in the skin of patients with different inflammatory diseases. A high percentage of these vessels in the dermis was associated with increased severity of CD3+ T-cell infiltration (P < 0.05). Additionally, CD3+ T cells were found both around the PNAd-expressing vessels and within the vessel lumen. PNAd-expressing vessels in cutaneous inflammatory diseases, characterized by CD3+ T-cell infiltration, could be a crucial entry point for T cells into the skin. Thus, selective targeting of these vessels could be beneficial in cutaneous inflammatory disease treatment.

The Percentage of PNAd-Expressing Vessels is Correlated with Disease Severity in Eosinophilic Chronic Rhinosinusitis

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is a chronic inflammatory condition of the paranasal sinuses characterized by intractable nasal polyps with prominent eosinophil infiltration. These eosinophils are presumably recruited from peripheral blood via vessels expressing peripheral lymph node addressin (PNAd), a set of glycoproteins decorated with 6-sulfo sialyl Lewis x (sLe^x) glycans that serve as L-selectin ligands. Based on the severity classification algorithm proposed by the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) study group, ECRS is divided into mild, moderate and severe groups; however, as yet there are few reports comparing the clinicopathological differences among these groups.

OBJECTIVE

Our goal was to elucidate clinicopathological differences among the three different severities of ECRS with special reference to eosinophils and PNAd-expressing vessels.

METHODS

We performed quantitative immunohistochemical analysis of PNAd-expressing vessels using surgical specimens of nasal polyps from patients exhibiting varying severity of ECRS (n = 35) and from individuals with non-ECRS (n = 10). To this end, we immunostained tissue sections with anti-PNAd and anti-CD34 monoclonal antibodies, and then determined the number of vessels immunolabeled with each antibody.

RESULTS

The number of eosinophils infiltrating nasal polyps was correlated with ECRS severity. We also found that the PNAd + /CD34 + vessel ratio, namely, the percentage of PNAd-expressing vessels among all vessels, was positively correlated not only with ECRS severity but also with the number of eosinophils infiltrating nasal polyps formed in ECRS.

CONCLUSION

These results strongly suggest that PNAd-expressing vessels play at least a partial role in eosinophil recruitment to nasal polyps and consequent severity of ECRS.

Therapeutic effects of nerve growth factor-targeting therapy on bladder overactivity in rats with prostatic inflammation

BACKGROUND

The present study examined the effect of liposomes conjugated with antisense oligonucleotide of nerve growth factor (NGF-OND) on local overexpression of NGF and bladder overactivity using rats with prostatic inflammation (PI).

METHODS

Male Sprague-Dawley rats were divided into three groups: (1) Control group; intact rats, (2) PI-NS group; rats with PI and intravesical instillation of normal saline (NS), (3) PI-OND group; rats with PI and intravesical instillation of NGF-OND. On Day 0, PI was induced by intraprostatic 5%-formalin injection. On Day 14, NGF-OND or NS was instilled directly into the bladder after laparotomy. On Day 28, therapeutic effects of NGF-OND were evaluated by awake cystometry and histological analysis as well as reverse-transcription polymerase chain reaction measurements of messenger RNA (mRNA) levels of NGF in the bladder and prostate, inflammatory markers in the prostate, C-fiber afferent markers, and an A-type K⁺ channel α-subunit (Kv 1.4) in L6-S1 dorsal root ganglia (DRG).

RESULTS

Intravesical NFG-OND treatment reduced PI-induced overexpression of NGF in both bladder and prostate, and reduced PI-induced bladder overactivity evident as longer intercontraction intervals in association with reductions of TRPV1 and TRPA1 mRNA expression levels in DRG. mRNA expression of Kv1.4 in DRG was reduced after PI, but improved in the PI-OND group.

CONCLUSIONS

These results indicate that NGF locally expressed in the bladder is an important mediator inducing bladder overactivity with upregulation of C-fiber afferent markers and downregulation of an A-type K⁺ channel subunit in DRG following PI, and that liposome-based, local NGF-targeting therapy could be effective for not only bladder overactivity and afferent sensitization, but also PI. Thus, local blockade of NGF in the bladder could be a therapeutic modality for male LUTS due to BPH with PI.

The Conspicuousness of High Endothelial Venules in Angioimmunoblastic T-cell Lymphoma Is Due to Increased Cross-sectional Area, Not Increased Distribution Density

Angioimmunoblastic T-cell lymphoma (AITL) is a T-cell lymphoma of follicular helper T-cell origin. Histologically, neoplastic T-cells proliferate to form clusters adjacent to or between arborizing high endothelial venules (HEVs). HEVs in normal lymph nodes express sulfated glycans called peripheral lymph node addressin (PNAd); however, it remains unclear whether PNAd is also expressed on HEVs in AITL. Furthermore, although it is widely accepted that HEVs are conspicuous in AITL due to their proliferation, quantitative histological support for this concept is lacking. To investigate these issues, we employed monoclonal antibodies recognizing PNAd, namely, MECA-79, HECA-452, and 297-11A, and performed quantitative immunohistochemical analysis of HEVs in 36 AITL-affected and 67 normal lymph nodes. Staining with all three antibodies confirmed that AITL HEVs express PNAd. Moreover, AITL HEVs were bound calcium-dependently by L-selectin-IgM fusion proteins, indicating that they function in the recruitment of L-selectin-expressing lymphocytes. Unexpectedly, HEV distribution density was not increased but rather decreased in AITL compared with normal lymph nodes, but HEV cross-sectional area in AITL was significantly greater than that seen in normal lymph nodes. Overall, these results indicate that the prominence of AITL HEVs is likely due to increased cross-sectional area rather than increased distribution density.

High endothelial venules (HEVs) in immunity, inflammation and cancer

High endothelial venules (HEVs) are specialized blood vessels mediating lymphocyte trafficking to lymph nodes (LNs) and other secondary lymphoid organs. By supporting high levels of lymphocyte extravasation from the blood, HEVs play an essential role in lymphocyte recirculation and immune surveillance for foreign invaders (bacterial and viral infections) and alterations in the body’s own cells (neoantigens in cancer). The HEV network expands during inflammation in immune-stimulated LNs and is profoundly remodeled in metastatic and tumor-draining LNs. HEV-like blood vessels expressing high levels of the HEV-specific sulfated MECA-79 antigens are induced in non-lymphoid tissues at sites of chronic inflammation in many human inflammatory and allergic diseases, including rheumatoid arthritis, Crohn’s disease, allergic rhinitis and asthma. Such vessels are believed to contribute to the amplification and maintenance of chronic inflammation. MECA-79⁺ tumor-associated HEVs (TA-HEVs) are frequently found in human tumors in CD3⁺ T cell-rich areas or CD20⁺ B-cell rich tertiary lymphoid structures (TLSs). TA-HEVs have been proposed to play important roles in lymphocyte entry into tumors, a process essential for successful antitumor immunity and lymphocyte-mediated cancer immunotherapy with immune checkpoint inhibitors, vaccines or adoptive T cell therapy. In this review, we highlight the phenotype and function of HEVs in homeostatic, inflamed and tumor-draining lymph nodes, and those of HEV-like blood vessels in chronic inflammatory diseases. Furthermore, we discuss the role and regulation of TA-HEVs in human cancer and mouse tumor models.

Induction of High Endothelial Venule-like Vessels in Oral and Cutaneous Lichen Planus: A Comparative Study

Lichen planus (LP) is a chronic inflammatory mucocutaneous disease involving the oral mucosa and skin. Both oral LP (OLP) and cutaneous LP (CLP) are histopathologically characterized by dense subepithelial lymphocyte infiltrates; however, the mechanisms underlying lymphocyte recruitment to sites of LP lesions are not fully understood. Here, we assessed the induction of peripheral lymph node addressin (PNAd)-expressing high endothelial venule (HEV)-like vessels in 19 OLP and 17 CLP cases. To do so, we performed immunohistochemical staining for PNAd and CD34, followed by quantitative analysis. We also conducted triple immunohistochemistry for PNAd and either CD3 and CD20 or CD4 and CD8 to identify the lymphocyte subset preferentially recruited via HEV-like vessels. PNAd-expressing HEV-like vessels were induced in and around lymphocyte aggregates in all cases of OLP and in 10 of 17 CLP cases, and these vessels were more frequently observed in OLP relative to CLP. Although the number of T-cells attached per HEV-like vessel exceeded the number of B-cells in both OLP and CLP, the number of CD4⁺ T-cells attached was greater than the number of CD8⁺ T-cells only in OLP. These findings combined suggest that PNAd-expressing HEV-like vessels play a more important role in the pathogenesis of OLP compared with CLP.

High Endothelial Venule with Concomitant High CD8+ Tumor-Infiltrating Lymphocytes Is Associated with a Favorable Prognosis in Resected Gastric Cancer

CD8+ tumor-infiltrating lymphocytes (TILs) play a major role in antitumor immunity. High endothelial venules (HEVs) are related to diverse immune cells in solid tumors. We analyzed CD8+ and Foxp3+ TILs in combination with HEVs to determine their prognostic role in advanced gastric cancer (AGC). We enrolled 157 patients with AGC in this study. The densities of CD8+ TILs and Foxp3+ TILs were calculated using immunohistochemical staining. HEVs were evaluated by MECA-79 expression. HEVs were identified in 60 (38.2%) cases and was significantly associated with an increased number of CD8+ TILs (p = 0.027) but not of Foxp3+ TILs (p = 0.455) and CD20+ TILs (p = 0.163). A high CD8+/HEV+ level was significantly associated with nodal metastasis (p = 0.048). In survival analysis, patients with high CD8+/HEV+ levels demonstrated the longest overall survival (OS) (p = 0.015). Furthermore, a high CD8+/HEV+ level was an independent prognostic factor in AGC (p = 0.011; hazard ratio (HR) = 0.435; 95% confidence interval (CI) = 0.245–0.837). HEVs were found to play an important role in antitumor immunity associated with CD8+ TILs in AGC. This analysis of HEVs and CD8+ TILs helps stratify patients with AGC and sheds light on tumor immunity.

Duration of smoking cessation is negatively associated with the magnitude of chronic prostatic inflammation and storage dysfunction in patients with benign prostatic hyperplasia

OBJECTIVES

To evaluate the impact of smoking and the benefit of smoking cessation on lower urinary tract function and prostatic inflammation in patients with benign prostatic hyperplasia.

METHODS

The medical records of 118 benign prostatic hyperplasia patients who underwent transurethral prostatic surgery between 2006 and 2016 were analyzed. Their smoking history was confirmed. The relationship between smoking and main clinical parameters, International Prostate Symptom Scores, uroflowmetry, pressure flow study, magnitude of prostatic inflammation and the level of serum C-reactive protein was investigated. Furthermore, the relationships between smoking cessation and these clinical parameters were assessed.

RESULTS

The International Prostate Symptom Scores for straining among the non-smokers were significantly lower than those of the smokers (1.71 vs 2.60, P = 0.029). In the pressure flow study, there were negative correlations between the duration of smoking and strong desire to void (correlation coefficient -0.314, P = 0.013), urgency (correlation coefficient -0.349, P = 0.008) and bladder volume at initial detrusor overactivity (correlation coefficient -0.417, P = 0.021). The duration of smoking cessation was negatively correlated with the magnitude of chronic prostatic inflammation (correlation coefficient -0.253, P = 0.027). In the pressure flow study, the duration of smoking cessation was positively correlated with urgency (correlation coefficient 0.286, P = 0.030) and maximum cystometric capacity (correlation coefficient 0.241, P = 0.050).

CONCLUSIONS

Smoking could be a risk factor for the exacerbation of storage dysfunction in benign prostatic hyperplasia patients. Smoking cessation is effective in improving chronic prostatic inflammation and storage dysfunction.

Urethral dysfunction in a rat model of chemically induced prostatic inflammation: potential involvement of the MRP5 pump

Prostate inflammation (PI) is a clinical condition associated with infection and/or inflammation of the prostate. It is a common disease frequently associated to lower urinary tract (LUT) symptoms. The urethra is an understudied structure in the LUT and plays a fundamental role in the urinary cycle. Here, we proposed to evaluate the effect of PI on the urethra tissue. Male Sprague-Dawley rats were used, and PI was induced by formalin injection into the ventral lobes of the prostate. The pelvic urethra at the prostatic level was harvested for histological analysis, contraction (electrical field stimulation and phenylephrine), and relaxation (sodium nitroprusside/MK-571) experiments. Various gene targets [cytochrome c oxidase subunit 2, transforming growth factor-β₁, interleukin-1β, hypoxia-inducible factor-1α, α_1A-adrenoceptor, inositol 1,4,5-trisphosphate receptor type 1, voltage-gated Ca²⁺ channel subunit-α_1D, neuronal nitric oxide synthase, soluble guanylyl cyclase, phosphodiesterase 5A, protein kinase CGMP-dependent 1, and multidrug resistance-associated protein 5 (MRP5; ATP-binding cassette subfamily C member 5)] were quantified, and cGMP levels were measured. No histological changes were detected, and functional assays revealed decreased contraction and increased relaxation of urethras from the PI group. The addition of MK-571 to functional assays increased urethral relaxation. Genes associated with inflammation were upregulated in urethras from the PI group, such as cytochrome oxidase c subunit 2, transforming growth factor-β₁, interleukin-1β, and hypoxia-inducible factor-1α. We also found increased expression of L-type Ca²⁺ channels and the neuronal nitric oxide synthase enzyme and decreased expression of the MRP5 pump. Finally, cGMP production was enhanced in urethral tissue of PI animals. The results indicate that PI is associated with proinflammatory gene expression in the urethra without histologically evident inflammation and that PI produces a dysfunctional urethra and MRP5 pump downregulation, which results in cGMP accumulation inside the cell. These findings would help to better understand LUT dysfunctions associated with PI and the role of MRP pumps in the control of LUT function.

Preferential expression of sialyl 6'-sulfo N-acetyllactosamine-capped O-glycans on high endothelial venules in human peripheral lymph nodes

Lymphocyte "homing", the physiologic trafficking of lymphocytes from the circulation to secondary lymphoid organs, is regulated by sequential adhesive interactions between lymphocytes and endothelial cells that constitute high endothelial venules (HEVs). Initial lymphocyte "rolling" is mediated by relatively weak, transient adhesive interactions between L-selectin expressed on lymphocytes and sulfated mucin-type O-glycans expressed on HEVs. Keratan sulfate galactose (Gal)-6-O-sulfotransferase (KSGal6ST) catalyzes 6-O-sulfation of Gal in keratan sulfate glycosaminoglycan chains but also transfers sulfate to Gal in much shorter glycan chains, such as sialylated N-acetyllactosamine (LacNAc)-capped O-glycans. In mice, KSGal6ST is reportedly expressed in HEVs and functions in synthesizing 6-sulfo Gal-containing O-glycans on HEVs. However, in humans, the presence of 6-sulfo Gal-containing O-glycans on HEVs is not reported. Employing the newly developed monoclonal antibody 297-11A, which recognizes non-sialylated terminal 6'-sulfo LacNAc, we demonstrate that sialyl 6'-sulfo (and/or 6,6'-disulfo) LacNAc-capped O-glycans are preferentially displayed on HEVs in human peripheral lymph nodes (PLNs) and to a lesser extent in mesenteric LNs (MLNs) but not in Peyer's patches (PPs). We also found that the scaffold protein mucosal addressin cell adhesion molecule 1 (MAdCAM-1), which is expressed on HEVs in PPs and MLNs but not PLNs, was modified by 297-11A-positive sulfated glycans less efficiently than was CD34. Moreover, 297-11A-positive sulfated glycans were also displayed on HEV-like vessels induced in tumor-infiltrating lymphocyte (TIL) aggregates formed in various cancers. These findings collectively indicate that 297-11A-positive sulfated glycans potentially play a role in physiologic lymphocyte homing as well as in lymphocyte recruitment under pathologic conditions.

Induction of peripheral lymph node addressin in human nasal mucosa with eosinophilic chronic rhinosinusitis

Eosinophilic chronic rhinosinusitis (ECRS) is characterised by formation of nasal polyps with prominent eosinophilic infiltration; however, how eosinophils are recruited in this pathological setting remains unclear. In the present study, we carried out quantitative immunohistochemical analysis of nasal polyps associated with ECRS (n=30) and non-ECRS (n=30) to evaluate expression of an L-selectin ligand peripheral lymph node addressin (PNAd) on vascular endothelial cells. We found that PNAd was induced primarily on the luminal surface of venular vessels present in nasal mucosa in both ECRS and non-ECRS, while the number of PNAd-expressing vessels in ECRS significantly exceeded that seen in non-ECRS. Moreover, the number of eosinophils attached to the luminal surface of PNAd-expressing vessels in ECRS was significantly greater than that in non-ECRS, while the number of neutrophils and lymphocytes attached did not differ significantly between conditions. Furthermore, eosinophils, which express cell surface L-selectin, adhered to PNAd-expressing Chinese hamster ovary (CHO) cells in a calcium-dependent manner, and that adhesion was significantly inhibited by pretreatment of eosinophils with DREG-56, an anti-human L-selectin monoclonal antibody. These findings combined suggest that interaction between L-selectin and PNAd plays at least a partial role in eosinophil recruitment in human nasal mucosa with ECRS.

Prostatic stromal inflammation is associated with bladder outlet obstruction in patients with benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common urologic disease in older men. Prostatic inflammation research has focused on the magnitude of inflammation; its location has received little attention. We investigated whether the anatomic location of prostatic inflammation is related to the severity of lower urinary tract symptoms (LUTS), measured subjectively and objectively.

METHODS

We retrospectively analyzed hematoxylin+eosin-stained tissue specimens from 179 BPH patients who underwent transurethral resection of the prostate (TURP) or holmium laser enucleation of the prostate (HoLEP). Chronic prostatic inflammation was assessed by the grade (lymphocyte density), extent (lymphocyte distribution), and location of inflammation. Each inflammation-finding type was evaluated in relation to these clinical parameters: age, prostate volume, prostate-specific antigen (PSA) value, body mass index (BMI), the frequency of acute urinary retention (AUR) episodes, the international prostatic symptom score (IPSS), and urodynamic study results.

RESULTS

The magnitude and extent of inflammation were not associated with any clinical parameters. We classified the BPH patients into stromal (n = 72) versus non-stromal (n = 105) groups based on their inflammation's dominant location. The stromal group's prostatic volume was significantly larger than the non-stromal group's (63.8 vs 53.8 mL; P = 0.032). AUR episodes were more significantly frequent in the stromal group (36.1% vs 11.4%; P = 0.006). Between-group differences in storage parameters (ie, maximum cystometric capacity) in the urodynamic study were not significantly different. Voiding parameters differed significantly between the stromal and non-stromal groups: maximum detrusor pressure (maxPdet) (116.8 vs 94.5 cmH₂ O, P = 0.014), Pdet at the maximum flow rate (Qmax) (95.8 vs 75.4 cmH₂ O, P = 0.014), and the bladder outlet obstruction index (BOOI) (78.5 vs 56.3, P = 0.014). The stromal group's Qmax was significantly lower than the non-stromal group's (7.3 vs 9.8 mL/s, P = 0.004).

CONCLUSIONS

The location of inflammation in the prostate might be an important factor affecting the severity of LUTS, especially voiding dysfunction.