Koumine regulates macrophage M1/M2 polarization via TSPO, alleviating sepsis-associated liver injury in mice.

BACKGROUND: Translocator protein (TSPO) is an 18-kDa transmembrane protein found primarily in the mitochondrial outer membrane, and it is implicated in inflammatory responses, such as cytokine release. Koumine (KM) is an indole alkaloid extracted from Gelsemium elegans Benth. It has been reported to be a high-affinity ligand of TSPO and to exert anti-inflammatory and immunomodulatory effects in our recent studies. However, the protective effect of KM on sepsis-associated liver injury (SALI) and its mechanisms are unknown. PURPOSE: To explore the role of TSPO in SALI and then further explore the protective effect and mechanism of KM on SALI. METHODS: The effect of KM on the survival rate of septic mice was confirmed in mouse models of caecal ligation and puncture (CLP)-induced and lipopolysaccharide (LPS)-induced sepsis. The protective effect of KM on CLP-induced SALI was comprehensively evaluated by observing the morphology of the mouse liver and measuring liver injury markers. The serum cytokine content was detected in mice by flow cytometry. Macrophage polarization in the liver was examined using western blotting. TSPO knockout mice were used to explore the role of TSPO in sepsis liver injury and verify the protective effect of KM on sepsis liver injury through TSPO. RESULTS: KM significantly improved the survival rate of both LPS- and CLP-induced sepsis in mice. KM has a significant liver protective effect on CLP-induced sepsis in mice. KM treatment ameliorated liver ischaemia, improved liver pathological injuries, and decreased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and proinflammatory cytokines in serum. Western blotting results showed that KM inhibited M1 polarization of macrophages and promoted M2 polarization. In TSPO knockout mice, we found that TSPO knockout can improve the survival rate of septic mice, ameliorate liver ischaemia, improve liver pathological injuries, and decrease the levels of ALT, AST, and LDH. In addition, TSPO knockout inhibits the M1 polarization of macrophages in the liver of septic mice and promotes M2 polarization and the serum levels of proinflammatory cytokines. Interestingly, in TSPO knockout septic mice, these protective effects of KM were no longer effective. CONCLUSIONS: We report for the first time that TSPO plays a critical role in sepsis-associated liver injury by regulating the polarization of liver macrophages and reducing the inflammatory response. KM, a TSPO ligand, is a potentially desirable candidate for the treatment of SALI that may regulate macrophage M1/M2 polarization through TSPO in the liver.

Increased CCR7loPD-1hiCXCR5+CD4+ T Cells in Peripheral Blood Mononuclear Cells Are Correlated with Immune Activation in Patients with Chronic HBV Infection.

T follicular helper cells (Tfh cells) affect essential immune pathogenesis in chronic hepatitis B virus (HBV) infection. The CCR7loPD-1hi Tfh subset has a partial Tfh effector phenotype and is associated with active Tfh differentiation, whereas the CCR7hiPD-1lo Tfh subset is a resting phenotype. We recruited 20 healthy volunteers and 77 patients with chronic HBV infection, including those in the immune tolerant (IT) phase (n=19), immune clearance (IC) phase (n=20), low replicative (LR) phase (n=18), and reactivation (RA) phase (n=20). The expression of CD4, CXCR5, PD-1, and CCR7 was detected in T cells from peripheral blood by flow cytometry. The frequency of the CCR7loPD-1hi T subset was significantly higher in the patients than in the healthy controls (14.92±4.87% vs 12.23±2.95%, p=0.018). The frequency of this Tfh subset in the IC group (18.42%±3.08) was increased compared with the IT group (11.94±2.87%, p=0.001) and LR group (13.65±4.93%, p=0.031) and was higher in the RA group than in the IT group (16.03±5.37% vs 11.94±2.87%, p=0.030). We observed a weak positive correlation between the CCR7loPD-1hi Tfh subset population and the alanine transaminase (ALT) level (r=0.370, p=0.001). The CCR7loPD-1h Tfh subset in the chronic HBV-infected patients was elevated to various degrees among the different immune phases. CCR7loPD-1hiCXCR5+CD4+ T cells are correlated with the immune status of chronic HBV infection patients and may be developed as a potential indicator for antiviral treatment.

Expression of MicroRNA-155 is Downregulated in Peripheral Blood Mononuclear Cells of Chronic Hepatitis B Patients.

BACKGROUND: Persistent hepatitis B virus (HBV) infection is sustained by inadequate immune responses, either natural or acquired. Recent studies have suggested that immune responses to viral infection may be affected by microRNA (miR)-155, via its involvement in immune cell differentiation and maturation. However, little is known on the specific interaction between miR-155 and HBV in host antiviral immunity. OBJECTIVES: This study evaluated the levels of miR-155 in peripheral blood mononuclear cells (PBMCs) of chronic hepatitis B (CHB) patients, relative to that of healthy subjects, and investigated an association between miR-155 levels and HBV DNA or alanine aminotransferase (ALT). PATIENTS AND METHODS: Total RNA was extracted from peripheral venous blood samples of 90 treatment-naive patients with chronic HBV infection and 20 healthy volunteers. The levels of miR-155 in the PBMCs were measured by real-time quantitative polymerase chain reaction. Serum HBV DNA and liver enzymes were estimated using standard clinical laboratory methods. RESULTS: In the HBV-infected patients, the miR-155 levels were significantly lower than in the healthy controls (P = 0.001). Chronic HBV-infected patients with elevated ALT had higher levels of miR-155 compared with patients with normal ALT (P = 0.014). No correlations were found between miR-155 and ALT or HBV DNA. CONCLUSIONS: The miR-155 appeared to be suppressed during HBV infection. The significantly higher miR-155 levels in ALT-elevated patients infected with HBV suggest that miR-155 levels in PBMCs correlate with the immune state of patients with chronic HBV infection.

Clinicopathologic and prognostic relevance of ARID1A protein loss in colorectal cancer.

AIM: To explore the association between AT-rich interactive domain 1A (ARID1A) protein loss by immunohistochemistry and both clinicopathologic characteristics and prognosis in patients with colorectal cancer. METHODS: We retrospectively collected clinicopathologic data and archived paraffin-embedded primary colorectal cancer samples from 209 patients, including 111 patients with colon cancer and 98 patients with rectal cancer. The tumor stage ranged from stage I to stage IV according to the 7(th) edition of the American Joint Committee on Cancer tumor-node-metastasis (TNM) staging system. All patients underwent resection of primary colorectal tumors. The expression of ARID1A protein in primary colorectal cancer tissues was examined by immunohistochemical staining. The clinicopathologic association and survival relevance of ARID1A protein loss in colorectal cancer were analyzed. RESULTS: ARID1A loss by immunohistochemistry was not rare in primary colorectal cancer tumors (25.8%). There were 7.4%, 24.1%, 22.2% and 46.3% of patients with ARID1A loss staged at TNM stage I, II, III and IV, respectively, compared with 20.0%, 22.6%, 27.7% and 29.7% of patients without ARID1A loss staged at TNM stage I, II, III and IV, respectively. In patients with ARID1A loss, the distant metastasis rate was 46.3%. However, only 29.7% of patients without ARID1A loss were found to have distant metastasis. In terms of pathologic differentiation, there were 25.9%, 66.7% and 7.4% with poorly, moderately and well differentiated tumors in patients with ARID1A loss, and 14.2%, 72.3% and 13.5% with poorly, moderately and well differentiated tumors in patients without ARID1A loss, respectively. ARID1A loss was associated with late TNM stage (P = 0.020), distant metastasis (P = 0.026), and poor pathological classification (P = 0.035). However, patients with positive ARID1A had worse overall survival compared to those with negative ARID1A in stage IV colorectal cancer (HR = 2.49, 95%CI: 1.13-5.51). CONCLUSION: ARID1A protein loss is associated with clinicopathologic characteristics in colorectal cancer patients and with survival in stage IV patients.