Transient increase in circulating myeloid-derived suppressor cells after partial bladder outlet obstruction

Myeloid-derived suppressor cells and pulmonary hypertension

Pulmonary hypertension (PH) is a chronic pulmonary vascular disorder characterized by an increase in pulmonary vascular resistance and pulmonary arterial pressure. The detailed molecular mechanisms remain unclear. In recent decades, increasing evidence shows that altered immune microenvironment, comprised of immune cells, mesenchymal cells, extra-cellular matrix and signaling molecules, might induce the development of PH. Myeloid-derived suppressor cells (MDSCs) have been proposed over 30 years, and the functional importance of MDSCs in the immune system is appreciated recently. MDSCs are a heterogeneous group of cells that expand during cancer, chronic inflammation and infection, which have a remarkable ability to suppress T-cell responses and may exacerbate the development of diseases. Thus, targeting MDSCs has become a novel strategy to overcome immune evasion, especially in tumor immunotherapy. Nowadays, severe PH is accepted as a cancer-like disease, and MDSCs are closely related to the development and prognosis of PH. Here, we review the relationship between MDSCs and PH with respect to immune cells, cytokines, chemokines and metabolism, hoping that the key therapeutic targets of MDSCs can be identified in the treatment of PH, especially in severe PH.

Cytokine-Induced Myeloid-Derived Suppressor Cells Demonstrate Their Immunoregulatory Functions to Prolong the Survival of Diabetic Mice

Type 1 diabetes is an inflammatory state. Myeloid-derived suppressive cells (MDSCs) originate from immature myeloid cells and quickly expand to control host immunity during infection, inflammation, trauma, and cancer. This study presents an ex vivo procedure to develop MDSCs from bone marrow cells propagated from granulocyte-macrophage-colony-stimulating factor (GM-CSF), interleukin (IL)-6, and IL-1β cytokines expressing immature morphology and high immunosuppression of T-cell proliferation. The adoptive transfer of cytokine-induced MDSCs (cMDSCs) improved the hyperglycemic state and prolonged the diabetes-free survival of nonobese diabetic (NOD) mice with severe combined immune deficiency (SCID) induced by reactive splenic T cells harvested from NOD mice. In addition, the application of cMDSCs reduced fibronectin production in the renal glomeruli and improved renal function and proteinuria in diabetic mice. Moreover, cMDSCs use mitigated pancreatic insulitis to restore insulin production and reduce the levels of HbA1c. In conclusion, administering cMDSCs propagated from GM-CSF, IL-6, and IL-1β cytokines provides an alternative immunotherapy protocol for treating diabetic pancreatic insulitis and renal nephropathy.

Systematic review of urinary biomarkers of female bladder outlet obstruction (fBOO)

Objective: Diagnosis of bladder outlet obstruction (BOO) in females is often challenging, not only because of the overlap in storage and voiding symptoms in women with various etiologies of lower urinary tract (LUT) dysfunction but also due to the lack of standardized urodynamic criteria to define the condition. There is an unmet need of biologic markers to evaluate BOO in females as an adjunct to other clinical criteria. We sought to elucidate the role of urinary biomarkers in female BOO. Material and methods: We performed a systematic review of studies involving urinary biomarkers in female BOO. The search was performed in PubMed. A total of 58 papers were retrieved and 2 were included for final analysis.Results: Currently, there are no validated biologic markers for female BOO available. Having a biomarker that can be obtained through a urine sample will be an invaluable tool to evaluate and counsel patients with LUT symptoms and possible BOO. The use of NGF as an indicator of BOO in female patients seems to be promising: NGF levels are elevated in women with BOO when compared with normal controls. Conclusions: We found that NGF levels may be applied as a useful biomarker in the diagnosis and evaluation of female patients with BOO symptoms. It will not completely replace other clinical diagnostic tools such as formal urodynamic testing but play a role as a supplement to it. Nevertheless, further studies should be conducted to establish NGF levels as a female BOO biomarker and a routine testing modality.

Human amniotic fluid stem cells can alleviate detrusor dysfunction caused by bladder outlet obstruction in rats

The present study examined whether bladder detrusor dysfunction due to partial bladder outlet obstruction (pBOO) could be improved after the treatment of human amniotic fluid stem cells (hAFSCs). 72 female rats were grouped into sham operation, pBOO, and pBOO with hAFSCs treatment (pBOO + hAFSCs) for in vitro and in vivo studies. Bladder weight, bladder wall thickness, the ratio of collagen to smooth muscle and the levels of positive CD11b/c and HIS48 cells was significantly increased after pBOO but improved after hAFSCs treatment. Cystometries showed impaired bladder function after pBOO. Protein and mRNA levels of hypoxia inducible factor-1α, CCL2, interleukin-1β, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin, collagen I and collagen III were increased at 2 and/or 6 weeks, but proteins and mRNA expressions of protein gene product 9.5 were decreased at 2 and 6 weeks after pBOO. These abnormalities were improved after hAFSCs treatment. The expressions of TGF-β1 and CTGF in cultured detrusor cells of pBOO rats were increased but were improved after hAFSCs treatment. The present results showed hAFSCs treatment could improve bladder detrusor dysfunction in pBOO rats, which may be related to the reduction of inflammatory and pro-fibrotic markers in detrusor muscle cells.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.

A Review of Oxidative Stress and Urinary Dysfunction Caused by Bladder Outlet Obstruction and Treatments Using Antioxidants

Urinary dysfunction is a common pathological condition that can significantly decrease the quality of life. Bladder outlet obstruction (BOO) is a major cause of urinary dysfunction, and various lower urinary tract diseases including benign prostatic hyperplasia and urethral stricture disease cause BOO. According to the results of a variety of animal experiments on partial BOO (PBOO), there is a general agreement that ischemic conditions and repeated ischemia/reperfusion of the bladder are closely associated with BOO-induced bladder damage, and that increased oxidative stress by ischemia/reperfusion plays a crucial role in the pathological mechanisms underlying urinary dysfunction. Changes in biomarkers of oxidative stress in PBOO animal models support this association between oxidative stress and urinary dysfunction. Oxidative stress is defined as an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidants. Therefore, organizing the knowledge on the state of oxidative stress, changes in biomarkers, and biological roles of antioxidants in systemic and bladder tissues is essential to understand the detailed pathological characteristics of the urinary dysfunction caused by PBOO. Furthermore, information on drugs and supplements that have antioxidant effects is important for defining treatment strategies for urinary dysfunction with PBOO. In this review, we paid special attention to the following three issues; (1) changes in oxidative stress, including its biomarkers, (2) antioxidant status, and (3) previous reports on treatment strategies involving agents with antioxidative activity for urinary dysfunction caused by BOO. In particular, we provide systematic information on the detailed mechanisms underlying the antioxidative effects of agents used to treat PBOO. In addition, we show present research issues and research limitations, as well as suggest possible future antioxidant treatment strategies for patients with PBOO.

New frontiers in molecular and imaging research on evaluation and diagnosis of bladder outlet obstruction in women

Purpose

Diagnosis of bladder outlet obstruction (BOO) often presents a challenge in female patients. Traditional diagnostic elements such as symptom history and urodynamic data are rarely clear cut in women. Therefore, we sought to review the current literature on diagnosis of female BOO, focusing on new frontiers in the realm of molecular markers and imaging modalities.

Recent Findings

In addition to fluoroscopy in the setting of videourodynamics, ultrasound and MRI can augment the diagnosis and aid in therapeutic planning in certain etiologies of female BOO. Furthermore, multiple potential biomarkers (i.e. nerve growth factor, prostaglandins, ATP) that have been studied in correlation to BOO in animal models as well as human subjects hold promise for diagnostic applications.

Summary

These novel techniques may augment standard clinical and urodynamic evaluation of BOO in females. Future directions include further studies of each of these biomarkers in female patients with BOO compared to normal controls to test their feasibility as potential screening tools.

The relevance of immune responses to partial bladder outlet obstruction and reversal

AIMS

Partial bladder outlet obstruction (PBOO) causes tissue inflammation, a significant increase in markers of systemic oxidative stress, and proliferation of circulating myeloid-derived suppressor cells. Here, we investigated the regulatory mechanisms underlying inflammation and helper T cell involvement in PBOO.

METHODS

Surgical PBOO was performed in four groups of rats: control (C), obstruction at 2 (O2) and 4 (O4) weeks, and 4 weeks after the relief of PBOO (R4) (n = 6 each). The urinary levels of prostaglandin E metabolite (PGEM), expression of inflammatory cytokines (IL-6 and IL-17) in the bladder, numbers of peripheral blood regulatory T cells (Treg cells), and levels of TGF-β1 were assessed via immunohistochemistry, flow cytometry, or ELISA.

RESULTS

The levels of urinary PGEM, bladder IL-17, and TGF-β1 and the numbers of peripheral Treg cells (Foxp3) were all significantly increased at 2 and 4 weeks after PBOO. PGEM, IL-17, and Treg cells (Foxp3) were decreased after the relief of PBOO, while the levels of TGF-β1 continued to increase.

CONCLUSIONS

Transient PBOO triggers an acute, reversible increase in inflammatory cytokines and Treg cells. The distinct dynamics of individual inflammatory markers support their potential use as markers for monitoring bladder inflammation.