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Rickettsiosis includes a diversity of culture-negative non-specific systemic infections. Laboratory diagnosis of rickettsiosis is often not easy. In this 12-month study, six patients with a variety of rickettsia infections of the spotted fever group, typhus group and scrub typhus were diagnosed directly or indirectly by metagenomic next-generation sequencing (mNGS). The patient with Japanese spotted fever was rapidly made when mNGS analysis of the patient's blood revealed Rickettsia japonica sequences. For the two patients with Rickettsia felis chest infections, the bacterium was detected in the bronchoalveolar lavage of one case and lung biopsy of the other. Both patients had underlying malignancies, carcinoma of the breast and carcinoma of the lung respectively, and were on chemotherapy with immunosuppressive effect. For the remaining three patients who presented over a period of 13 weeks, all had fever, headache and the typical eschar. They also had increased serum transaminases and responded promptly to doxycycline. However, the Weil-Felix test results of all three patients were negative. Since we considered the three cases typical of rickettsiosis, we submitted their serum samples for mNGS analysis. Results showed that Orientia tsutsugamushi sequences were present in the serum of one case. In view of the positive mNGS results, we repeated the Weil-Felix test for the residual sera of all three patients and it revealed that those of the other two cases showed OX-19 titers of 1:640 and 1:160 respectively, inferring that these two patients probably had rickettsiosis of the typhus group. As for the patient positive for O. tsutsugamushi sequences, we also detected IgM for O. tsutsugamushi in the serum, which double confirmed that it was a case of scrub typhus. mNGS is an important molecular tool and can complement serology for laboratory diagnosis of rickettsiosis. Author summary: Rickettsiosis includes a diversity of systemic infections presented with non-specific symptoms. Laboratory diagnosis of rickettsiosis is often not easy. In this 12-month study, six patients with a variety of rickettsia infections were diagnosed directly or indirectly by metagenomic next-generation sequencing (mNGS). These include one patient with Japanese spotted fever in whom Rickettsia japonica sequences were detected in blood, two patients with Rickettsia felis chest infections in whom R. felis sequences were detected in respiratory samples, one patient with scrub typhus in whom Orientia tsutsugamushi sequences were detected in serum, and two patients with rickettsiosis of the typhus group. In particular, the last three patients had initial false-negative Weil-Felix test results performed in a central reference laboratory but the diagnosis of rickettsiosis was subsequently confirmed by mNGS and repeated serology. mNGS is an important diagnostic tool for rickettsiosis and other difficult-to-diagnose systemic infections. [ABSTRACT FROM AUTHOR]

On the basis of carbon tetrachloride (CCl4)induced liver fibrosis in rats, this study aims to investigate the dynamic changes in matrix metalloproteinase 1 (MMP1) and the tissue inhibitor of metalloproteinase 1 (TIMP1) in the antifibrotic process of Dahuang Zhechong Pill (DHZCP). A total of 50 male Sprague Dawley rats, aged 8 weeks, were randomly divided into 3 groups: the control group, the model group (the group treated with CCl4), and the treatment group (the group treated with CCl4 and DHZCP). Rats were sacrificed at Weeks 4 and 8. Liver tissues were separated for RNA sequencing and bioinformatics analysis. Real-time PCR, Western blot analysis, and histological staining were conducted to confirm the gene expression and pathological change in liver tissues. Compared with control group, rats in model group showed poor mental state and slow weight gain. The liver tissues of the rats in the model group exhibited a damaged hepatic lobule structure, fibrous connective tissue hyperplasia, and inflammatory cell infiltration among the hyperplastic tissues. DHZCP could significantly improve the appearance of rats and alleviate CCl4-induced fibrosis. Compared to model group, 798 differentially expressed mRNAs were found in the treatment group, of which 120 were up-regulated and 678 were down-regulated. Differentially expressed mRNAs between the CCl4-induced group and the DHZCP-treated group were mainly focused on the following KEGG pathways: focal adhesion, phagosome, tight junction, and ECM–receptor interactions. Relative to those in the control group, MMP1 was downregulated, whereas, TIMP1 and Col1A1 were upregulated in the CCl4-induced group at Weeks 4 and 8. DHZCP could reverse MMP1, TIMP1, and Col1A1 expression.DHZCP protects against liver injury and exerts an antifibrotic effect on liver fibrosis induced by CCl4 in rats. Its mechanism may be related to the upregulation of MMP1, downregulation of TIMP1, and promotion of collagen degradation.

Liver fibrosis occurs as a result of chronic liver lesions, which may subsequently develop into liver cirrhosis and hepatocellular carcinoma. The involvement of long noncoding RNAs (lncRNAs) in liver fibrosis is being increasingly recognized. However, the exact mechanisms and functions of the majority of lncRNAs are poorly characterized. In the present study, the hepatotoxic substance carbon tetrachloride (CCl4) was employed to induce liver fibrosis in an animal model and agenome-wide identification of lncRNAs in fibrotic liver tissues compared with CCl4 untreated liver tissues was performed using RNA sequencing. Sprague-Dawley rats were treated with CCl4 for 8 weeks. Histopathogical alterations were observed in liver tissues, and serum levels of alanine aminotransferase, aspartate aminotransferase, transforming growth factor-β1 and tumor necrosis factor-α were significantly higher, in the CCl4-treated group compared with the CCl4 untreated group. RNA sequencing of liver tissues demonstrated that 231 lncRNAs and 1,036 mRNAs were differentially expressed between the two groups. Furthermore, bioinformatics analysis demonstrated that the differentially expressed mRNAs were predominantly enriched in ‘ECM-receptor interaction’, ‘PI3K-Akt signaling pathway’ and ‘focal adhesion’ pathways, all of which are essential for liver fibrosis development. Validation of 12 significantly aberrant lncRNAs by reverse transcription-quantitative polymerase chain reaction indicated that the expression patterns of 11 lncRNAs were consistent with the sequencing data. Furthermore, overexpression of lncRNA NR_002155.1, which was markedly downregulated in CCl4-treated liver tissues, was demonstrated to inhibit HSC-T6 cell proliferation in vitro. In conclusion, the present study determined the expression patterns of mRNAs and lncRNAs in fibrotic liver tissue induced by CCl4. The identified differentially expressed lncRNAs may serve as novel diagnostic biomarkers and therapeutic targets for liver fibrosis. [ABSTRACT FROM AUTHOR]