Squalene-epoxidase-catalyzed 24(S),25-epoxycholesterol synthesis promotes trained-immunity-mediated antitumor activity.

The importance of trained immunity in antitumor immunity has been increasingly recognized, but the underlying metabolic regulation mechanisms remain incompletely understood. In this study, we find that squalene epoxidase (SQLE), a key enzyme in cholesterol synthesis, is required for ß-glucan-induced trained immunity in macrophages and ensuing antitumor activity. Unexpectedly, the shunt pathway, but not the classical cholesterol synthesis pathway, catalyzed by SQLE, is required for trained immunity induction. Specifically, 24(S),25-epoxycholesterol (24(S),25-EC), the shunt pathway metabolite, activates liver X receptor and increases chromatin accessibility to evoke innate immune memory. Meanwhile, SQLE-induced reactive oxygen species accumulation stabilizes hypoxia-inducible factor 1α protein for metabolic switching into glycolysis. Hence, our findings identify 24(S),25-EC as a key metabolite for trained immunity and provide important insights into how SQLE regulates trained-immunity-mediated antitumor activity.

Prognostic effect of CD73 in pancreatic ductal adenocarcinoma for disease-free survival after radical surgery.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a high potency of metastasis or recurrence after radical resection. Effective predictors for metastasis and recurrence postoperatively were dominant for the development of systemic adjuvant treatment regimens. The ATP hydrolase correlated gene CD73 was described as a promoter in tumor growth and immune escape of PDAC. However, there lacked research focused on the role of CD73 in PDAC metastasis. This study aimed to investigate the expression of CD73 in PDAC patients with different outcomes as well as the prognostic effect of CD73 for disease-free survival (DFS). METHODS: The expression level of CD73 in cancerous samples from 301 PDAC patients was evaluated by immunohistochemistry (IHC) and translated into a histochemistry score (H-score) by the HALO analysis system. Then, the CD73 H-score was involved in multivariate Cox regression along with other clinicopathological characteristics to find independent prognostic factors for DFS. Finally, a nomogram was constructed based on those independent prognostic factors for DFS prediction. RESULTS: Higher CD73 expression was found in PDAC patients with tumor metastasis postoperatively. Meanwhile, higher CD73 expressions were also investigated in PDAC patients diagnosed with advanced N stage and T stage. Furthermore, CD73 H-score along with tumor margin status, CA19-9, 8th N stage, and adjuvant chemotherapy was indicated as independent prognostic factors for DFS in PDAC patients. The nomogram based on these factors predicted DFS in a good manner. CONCLUSION: CD73 was associated with PDAC metastasis and served as an effective prognostic factor for DFS in PDAC patients after radical surgery.

Serum Amyloid a Predicts Prognosis and Chemotherapy Efficacy in Patients with Advanced Pancreatic Cancer.

Purpose: There is an urgent need to discover a predictive biomarker to help patients with advanced pancreatic cancer (APC) choose appropriate chemotherapy regimens. This study aimed to determine whether baseline serum amyloid A (SAA) levels were associated with overall survival (OS), progression-free survival (PFS), and treatment response in patients with APC received chemotherapy. Patients and Methods: This retrospective study included 268 patients with APC who received first-line chemotherapy at the Sun Yat-Sen University Cancer Center between January 2017 and December 2021. We examined the effect of baseline SAA on OS, PFS and chemotherapy response. The X-Tile program was used to determine the critical value for optimizing the significance of segmentation between Kaplan-Meier survival curves. The Kaplan-Meier curves and Cox regression analyses were used to analyze OS and PFS. Results: The best cut-off value of baseline SAA levels for OS stratification was 8.2 mg/L. Multivariate analyses showed that SAA was an independent predictor of OS (Hazard Ratio (HR) = 1.694, 95% Confidence Interval (CI) = 1.247-2.301, p = 0.001) and PFS (HR = 1.555, 95% CI = 1.152-2.098, p = 0.004). Low SAA was associated with longer OS (median, 15.7 months vs 10.0 months, p < 0.001) and PFS (median, 7.6 months vs 4.8 months, p < 0.001). The patients with a low SAA who received mFOLFIRINOX had longer OS (median, 28.5 months vs 15.1 months, p = 0.019) and PFS (median, 12.0 months vs 7.4 months, p = 0.035) than those who received nab-paclitaxel plus gemcitabine (AG) or SOXIRI, whereas there was no significant difference among the three chemotherapy regimens in patients with a high SAA. Conclusion: Owing to the rapid and simple analysis of peripheral blood, baseline SAA might be a useful clinical biomarker, not only as a prognostic biomarker for patients with APC, but also as a guide for the selection of chemotherapy regimens.

Notch1 Signaling Contributes to Mechanical Allodynia Associated with Cyclophosphamide-Induced Cystitis by Promoting Microglia Activation and Neuroinflammation.

AIMS: Notch1 signaling regulates microglia activation, which promotes neuroinflammation. Neuroinflammation plays an essential role in various kinds of pain sensation, including bladder-related pain in bladder pain syndrome/interstitial cystitis (BPS/IC). However, the impact of Notch1 signaling on mechanical allodynia in cyclophosphamide- (CYP-) induced cystitis is unclear. This study is aimed at determining whether and how Notch1 signaling modulates mechanical allodynia of CYP-induced cystitis. METHODS: CYP was peritoneally injected to establish a bladder pain syndrome/interstitial cystitis (BPS/IC) rat model. A γ-secretase inhibitor, DAPT, was intrathecally injected to modulate Notch1 signaling indirectly. Mechanical withdrawal threshold in the lower abdomen was measured with von Frey filaments using the up-down method. The expression of Notch1 signaling, Iba-1, OX-42, TNF-α, and IL-1ß in the L6-S1 spinal dorsal horn (SDH) was measured with Western blotting analysis and immunofluorescence staining. RESULTS: Notch1 and Notch intracellular domain (NICD) were both upregulated in the SDH of the cystitis group. Moreover, the expression of Notch1 and NICD was negatively correlated with the mechanical withdrawal threshold of the cystitis rats. Furthermore, treatment with DAPT attenuated mechanical allodynia in CYP-induced cystitis and inhibited microglia activation, leading to decreased production of TNF-α and IL-1ß. CONCLUSION: Notch1 signaling contributes to mechanical allodynia associated with CYP-induced cystitis by promoting microglia activation and neuroinflammation. Our study showed that inhibition of Notch1 signaling might have therapeutic value for treating pain symptoms in BPS/IC.

Human Umbilical Cord Mesenchymal Stem Cell Therapy Mitigates Interstitial Cystitis by Inhibiting Mast Cells.

BACKGROUND Interstitial cystitis (IC) is a recurrent and chronic inflammatory disease that compromises patients' quality of life. Effective treatments for IC are limited. This study aimed to evaluate the therapeutic potency of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) in an IC-induced rat model and investigate the potential molecular mechanism in a mast cell model (rat basophilic leukemia cells, RBL-2H3) in treating IC in a coculture system. MATERIAL AND METHODS The rat model of IC was induced by cyclophosphamide (CYP). Rats were randomly divided into 3 groups: sham, IC+PBS, and IC+MSC. In the coculture system, RBL-2H3 cells were sensitized overnight to Compound 48/80 (C48/80), cocultured with UC-MSCs for 3 days, and collected for subsequent experiments. RBL-2H3 cells were randomly divided into 3 groups: sham, C48, and UC-MSCs (C48+MSC). RESULTS The UC-MSCs marked by thymidine analog 5-ethynyl-2-deoxyuridine (EdU) were transplanted in the treatment group, and were densely distributed in the bladder. Accordingly, the conscious cystometry was measured and the bladder tissues were harvested. Compared with the sham group, the treated IC rats exhibited shorter bladder voiding intervals (307±35 vs 217±37 s; P<0.01), more integral epithelia, and less collagen fiber aggregation, infiltration and degranulation of mast cells, and inflammatory cytokines in the bladder tissue. In the coculture system, compared with the C48 group, the UC-MSC-treated RBL-2H3 cells had suppressed degranulation. CONCLUSIONS UC-MSCs treatment showed a promising therapeutic effect on treating IC in vivo and in vitro. UC-MSCs inhibit mast cell degranulation in IC and could be a potential therapeutic target to ameliorate inflammation in IC.

Normalization of magnesium deficiency attenuated mechanical allodynia, depressive-like behaviors, and memory deficits associated with cyclophosphamide-induced cystitis by inhibiting TNF-α/NF-κB signaling in female rats.

BACKGROUND: Bladder-related pain symptoms in patients with bladder pain syndrome/interstitial cystitis (BPS/IC) are often accompanied by depression and memory deficits. Magnesium deficiency contributes to neuroinflammation and is associated with pain, depression, and memory deficits. Neuroinflammation is involved in the mechanical allodynia of cyclophosphamide (CYP)-induced cystitis. Magnesium-L-Threonate (L-TAMS) supplementation can attenuate neuroinflammation. This study aimed to determine whether and how L-TAMS influences mechanical allodynia and accompanying depressive symptoms and memory deficits in CYP-induced cystitis. METHODS: Injection of CYP (50 mg/kg, intraperitoneally, every 3 days for 3 doses) was used to establish a rat model of BPS/IC. L-TAMS was administered in drinking water (604 mg·kg-1·day-1). Mechanical allodynia in the lower abdomen was assessed with von Frey filaments using the up-down method. Forced swim test (FST) and sucrose preference test (SPT) were used to measure depressive-like behaviors. Novel object recognition test (NORT) was used to detect short-term memory function. Concentrations of Mg2+ in serum and cerebrospinal fluid (CSF) were measured by calmagite chronometry. Western blot and immunofluorescence staining measured the expression of tumor necrosis factor-α/nuclear factor-κB (TNF-α/NF-κB), interleukin-1ß (IL-1ß), and N-methyl-D-aspartate receptor type 2B subunit (NR2B) of the N-methyl-D-aspartate receptor in the L6-S1 spinal dorsal horn (SDH) and hippocampus. RESULTS: Free Mg2+ was reduced in the serum and CSF of the CYP-induced cystitis rats on days 8, 12, and 20 after the first CYP injection. Magnesium deficiency in the serum and CSF correlated with the mechanical withdrawal threshold, depressive-like behaviors, and short-term memory deficits (STMD). Oral application of L-TAMS prevented magnesium deficiency and attenuated mechanical allodynia (n = 14) and normalized depressive-like behaviors (n = 10) and STMD (n = 10). The upregulation of TNF-α/NF-κB signaling and IL-1ß in the L6-S1 SDH or hippocampus was reversed by L-TAMS. The change in NR2B expression in the SDH and hippocampus in the cystitis model was normalized by L-TAMS. CONCLUSIONS: Normalization of magnesium deficiency by L-TAMS attenuated mechanical allodynia, depressive-like behaviors, and STMD in the CYP-induced cystitis model via inhibition of TNF-α/NF-κВ signaling and normalization of NR2B expression. Our study provides evidence that L-TAMS may have therapeutic value for treating pain and comorbid depression or memory deficits in BPS/IC patients.

BDNF promotes activation of astrocytes and microglia contributing to neuroinflammation and mechanical allodynia in cyclophosphamide-induced cystitis.

BACKGROUND: Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) often grieve over a low quality of life brought about by chronic pain. In our previous studies, we determined that neuroinflammation of the spinal dorsal horn (SDH) was associated with mechanisms of interstitial cystitis. Moreover, it has been shown that brain-derived neurotrophic factor (BDNF) participates in the regulation of neuroinflammation and pathological pain through BDNF-TrkB signaling; however, whether it plays a role in cyclophosphamide (CYP)-induced cystitis remains unclear. This study aimed to confirm whether BDNF-TrkB signaling modulates neuroinflammation and mechanical allodynia in CYP-induced cystitis and determine how it occurs. METHODS: Systemic intraperitoneal injection of CYP was performed to establish a rat cystitis model. BDNF-TrkB signaling was modulated by intraperitoneal injection of the TrkB receptor antagonist, ANA-12, or intrathecal injection of exogenous BDNF. Mechanical allodynia in the suprapubic region was assessed using the von Frey filaments test. The expression of BDNF, TrkB, p-TrkB, Iba1, GFAP, p-p38, p-JNK, IL-1ß, and TNF-α in the L6-S1 SDH was measured by Western blotting and immunofluorescence analysis. RESULTS: BDNF-TrkB signaling was upregulated significantly in the SDH after CYP was injected. Similarly, the expressions of Iba1, GFAP, p-p38, p-JNK, IL-1ß, and TNF-α in the SDH were all upregulated. Treatment with ANA-12 could attenuate mechanical allodynia, restrain activation of astrocytes and microglia and alleviate neuroinflammation. Besides, the intrathecal injection of exogenous BDNF further decreased the mechanical withdrawal threshold, promoted activation of astrocytes and microglia, and increased the release of TNF-α and IL-1ß in the SDH of our CYP-induced cystitis model. CONCLUSIONS: In our CYP-induced cystitis model, BDNF promoted the activation of astrocytes and microglia to release TNF-α and IL-1ß, aggravating neuroinflammation and leading to mechanical allodynia through BDNF-TrkB-p38/JNK signaling.

Neuregulin-1-ErbB signaling promotes microglia activation contributing to mechanical allodynia of cyclophosphamide-induced cystitis.

AIMS: Central sensitization playsimportant roles in cyclophosphamide (CYP)-induced cystitis. In addition, as a visceral pain, CYP-induced chronic pain shares common pathophysiological mechanisms with neuropathic pain. Previous studies demonstrated that neuregulin-1 (Nrg1)-ErbB signaling contributes to neuropathic pain, but whether and how this signaling influences mechanical allodynia in CYP-induced cystitis is unclear. This study aimed to determine whether and how Nrg1-ErbB signaling modulates mechanical allodynia in a CYP-induced cystitis rat model. METHODS: Systemic injection with CYP was used to establish a rat model of bladder pain syndrome/interstitial cystitis (BPS/IC). An irreversible ErbB family receptor inhibitor, PD168393, and exogenous Nrg1 were intrathecally injected to modulate Nrg1-ErbB signaling. Mechanical allodynia in the lower abdomen was assessed with von-Frey filaments using the up-down method. Western blot analysis and immunofluorescence staining were used to measure the expression of Nrg1-ErbB signaling, Iba-1, p-p38, and IL-1ß in the L6-S1 spinal dorsal horn (SDH). RESULTS: We observed upregulation of Nrg1-ErbB signaling as well as overexpression of the microglia activation markers Iba-1 and p-p38 and the proinflammatory factor, interleukin-1ß (IL-1ß), in the SDH of the cystitis group. Further, treatment with PD168393 attenuated mechanical allodynia in CYP-induced cystitis and inhibited microglia activation, leading to decreased production of IL-1ß. The inhibitor PD168393 reversed the algesic effect of exogenous Nrg1 on the cystitis model. CONCLUSIONS: Nrg1-ErbB signaling may promote microglia activation, contributing to mechanical allodynia of CYP-induced cystitis. Our study showed that modulation of Nrg1-ErbB signaling may have therapeutic value for treating pain symptoms in BPS/IC.