Qiao-Xiao Tong

Summary Immunopathological mechanisms of schistosomiasis, a debilitating parasitic disease, are still unclear. In this study, we investigated the involvement of CX3C chemokine ligand 1 (CX3CL1) and its sole receptor CX3CR1 in the development of liver fibrosis in schistosomiasis. The animal model of schistosomiasis was established by infection of C57BL/6 mice with Schistosoma japonicum cercariae; mice injected with carbon tetrachloride (CCl₄) were used as positive control of liver injury. After 4 and 8 weeks, the degree of liver lesions was assessed by hematoxylin and eosin staining, serum levels of hyaluronic acid (HA) were analyzed by a chemiluminescence immunoassay, liver fibrosis was evaluated by immunohistochemistry analysis of α-smooth muscle actin (α-SMA) expression, and CX3CL1 and CX3CR1 expression in the liver was measured by immunohistochemistry and real-time PCR. The results showed that at 8 weeks after Schistosoma infection, serum HA levels were increased and α-SMA-expressing cells appeared in the liver, indicating fibrogenesis. CX3CL1- and CX3CR1-positive cells were observed in the outer layer of granulomas formed around Schistosoma eggs in liver tissues, which was consistent with the significant upregulation of hepatic CX3CL1 and CX3CR1 mRNA expression at 4 and 8 weeks post-infection. Furthermore, correlation analysis revealed positive association between CX3CL1 and CX3CR1 expression and serum HA levels at 8 weeks post-infection, indicating a link between fibrogenesis and the CX3CL1/CX3CR1 axis in schistosomiasis. In conclusion, our data suggest the involvement of CX3CL1 and CX3CR1 in the progression of liver fibrosis caused by Schistosoma infection.

Background: Severe patients with 2019 novel coronavirus (2019-nCoV) pneumonia progressed rapidly to acute respiratory failure. We aimed to evaluate the definite efficacy and safety of corticosteroid in the treatment of severe COVID-19 pneumonia. Methods: Forty-six hospitalized patients with severe COVID-19 pneumonia hospitalized at Wuhan Union Hospital from January 20 to February 25, 2020, were retrospectively reviewed. The patients were divided into two groups based on whether they received corticosteroid treatment. The clinical symptoms and chest computed tomography(CT) results were compared. Results: A total of 26 patients received intravenous administration of methylprednisolone with a dosage of 1-2mg/kg/d for 5-7 days, while the remaining patients not. There was no significant difference in age, sex, comorbidities, clinical or laboratory parameters between the two groups on admission. The average number of days for body temperature back to the normal range was significantly shorter in patients with administration of methylprednisolone when compared to those without administration of methylprednisolone (2.06±0.28 vs. 5.29±0.70, P=0.010). The patients with administration of methylprednisolone had a faster improvement of SpO2, while patients without administration of methylprednisolone had a significantly longer interval of using supplemental oxygen therapy (8.2days[IQR 7.0-10.3] vs . 13.5days(IQR 10.3-16); P<0.001). In terms of chest CT, the absorption degree of the focus was significantly better in patients with administration of methylprednisolone. Conclusion: Our data indicate that in patients with severe COVID-19 pneumonia, early, low-dose and short-term application of corticosteroid was associated with a faster improvement of clinical symptoms and absorption of lung focus.

In recent years, an increasing number of studies have found that the interaction between CX3CL1 and its receptor plays an important role in a series of inflammatory, infectious, and neurological processes and in various cancers. Therefore, its therapeutic targeting represents a promising treatment strategy for diseases. This review summarizes the structure, biological function, and mechanism of signal transduction of CX3CL1 and its receptor, and introduces the research progress in CX3CL1 and its receptor in hepatitis, hepatic fibrosis, cirrhosis, and hepatoma.