BackgroundSepsis is a life-threatening complication of an infection and remains one of the leading causes of mortality in surgical patients. Bacteremia induces excessive inflammatory responses that result in multiple organ damage. Chronic helminth infection and helminth-derived materials have been found to immunomodulate host immune system to reduce inflammation against some allergic or inflammatory diseases. Schistosoma japonicum cystatin (Sj-Cys) is a cysteine protease inhibitor that induces regulatory T-cells and a potential immunomodulatory. The effect of Sj-Cys on reducing sepsis inflammation and mortality was investigated.MethodsSepsis was induced in BALB/c mice using cecal ligation and puncture (CLP), followed by intraperitoneal injection of different doses (10, 25 or 50 μg) of recombinant Sj-Cys (rSj-Cys). The therapeutic effect of rSj-Cys on sepsis was evaluated by observing the survival rates of mice for 96 h after CLP and the pathological injury of liver, kidney and lung by measuring the levels of alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN) and creatinine (Cr) in sera and the tissue sections pathology, and the expression of MyD88 in liver, kidney and lung tissues. The immunological mechanism was investigated by examining pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and IL-10 and TGF-β1 in mice sera and in culture of macrophages stimulated by lipopolysaccharides (LPS).ResultsrSj-Cys treatment provided significant therapeutic effects on CLP-induced sepsis in mice demonstrated with increased survival rates, alleviated overall disease severity and tissue injury of liver, kidney and lung. The rSj-Cys conferred therapeutic efficacy was associated with upregualted IL-10 and TGF-β1 cytokines and reduced pro-inflammatory cytokines TNF-α, IL-6, IL-1β. MyD88 expression in liver, kidney and lung tissues of rSj-Cys-treated mice was reduced. In vitro assay with macrophages also showed that rSj-Cys inhibited the release of pro-inflammatory cytokines and mediator nitric oxide (NO) after being stimulated by lipopolysaccharide (LPS).ConclusionsThe results suggest the anti-inflammatory potential of rSj-Cys as a promising therapeutic agent on sepsis. The immunological mechanism underlying its therapeutic effect may involve the downregulation of pro-inflammatory cytokines and upregulation of IL-10 and TGF-β1 cytokines possibly via downregulation of the TLR adaptor-transducer MyD88 pathway. The findings suggest rSj-Cys is a potential therapeutic agent for sepsis and other inflammatory diseases.

The aberrant expression of microRNA (miR)‑214 contributes to the regulation of normal and cancer cell biology, and is associated with human malignancies, however, it can operate in a contradictory manner. The role of miR‑214 in osteosarcoma remains to be fully elucidated. The aim of the present study was to investigate the effects of miR‑214 on osteosarcoma progression and tumor cell proliferation, and examine the molecular mechanism underlying osteosarcoma. The level of miR‑214 was determined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis in osteosarcoma and matched paracancerous tissues, and in human osteosarcoma cancer cell lines. The roles of miR‑214 in cell proliferation, survival and cell cycle were analyzed using miR‑214 lentivirus (LV‑miR‑214)‑infected osteosarcoma cells. In addition, the downstream target proteins in the Wnt/β‑catenin signaling pathway were evaluated using western blot analysis in the LV‑miR‑214‑infected cells. The LV‑miR‑214‑infected MG63 cells were also treated with exogenous β‑catenin for 24, 48 and 72 h, respectively, following which the expression of β‑catenin was measured using western blot analysis and survival was determined using a 3‑(4,5‑cimethylthiazol‑2‑yl)‑2,5‑diphenyl tetrazolium bromide (MTT) assay. The results of the RT‑qPCR analysis showed that the expression level of miR‑214 was significantly higher in the osteosarcoma tissues, compared with that in the matched paracancerous tissues, and the same was observed in the osteosarcoma cell lines. The MG63, Saos‑2 and U2OS cells were infected with the hsa‑mir‑214 lentivirus for 48 h, and the levels of miR‑214 were significantly upregulated in the human osteosarcoma cancer cells. The overexpression of miR‑214 in the MG‑63 and Saos‑2 cells promoted cell growth, and treatment of the cells with specific antisense‑microRNA oligonucleotides (AMOs) for miR‑214 for indicated durations reversed the effects of miR‑214. Additionally, the AMO‑treated MG63 cells showed G0/G1 phase arrest, suggesting that miR‑214 contributed to regulation of the cell cycle. In addition, the results of western blot analysis showed that, in the miR‑214 lentivirus‑infected cells, the levels of cyclin‑D1, c‑myc and lymphoid enhancer‑binding factor‑1 were significantly increased, compared with those in the control lentivirus‑infected cancer cells. Of note, infection with the miR‑214 lentivirus did not affect the levels of Wnt1, Wnt2, Wnt4, Axin or glycogen synthase kinase β in the U2OS cells, whereas the expression levels of β‑catenin in the MG63 cells and Saos‑2 cells were significantly increased. The addition of exogenous β‑catenin effectively reversed the efficiency of miR‑214‑specific AMOs, which was detected using an MTT assay. These data suggested the critical role of miR‑214 in human osteosarcoma via regulation of the Wnt/β‑catenin signaling pathway and demonstrated that miR‑214 is as an oncogene for human osteosarcoma.

Acute lung injury (ALI) is a common complication of systemic inflammation or sepsis with high morbidity and mortality. Although many studies have confirmed that helminth-derived proteins had strong immunomodulatory functions and could be used to treat inflammatory diseases, there is no report on the therapeutic effect of excretory-secretory products of Trichinella spiralis adult worms (Ts-AES) on sepsis-induced ALI. In this study, the therapeutic efficacy of Ts-AES on sepsis-induced ALI and the underlying immunological mechanism and the signaling pathway were investigated. The results indicated that after being treated with Ts-AES, the survival rate of mice with CLP-induced sepsis was significantly increased to 50% for 72 hours after CLP surgery compared to PBS control group with all mice died. The sepsis-induced ALI was largely mitigated characterized by reduced inflammation cell infiltration and pathological changes in lung tissue, with decreased lung injury scores and lung wet/dry weight ratio. The therapeutic efficacy of Ts-AES is associated with stimulated Tregs response with increased regulatory cytokines IL-10 and TGF-β and downregulated pro-inflammatory cytokines (TNF-α, IL-6, IL-1β). The expression of HMGB1, TLR2 and MyD88 in lung tissue was inhibited after treatment of Ts-AES. Our results demonstrated that Ts-AES play an important role in immunomodulation and confer a therapeutic effect on sepsis-induced ALI through inhibiting pro-inflammatory cytokines. The activation of Tregs and increased level of regulatory cytokines IL-10 and TGF-β are possibly involved in the immunomodulatory functions of Ts-AES through HMGB1/TLR2/MyD88 signal pathway. The findings suggest Ts-AES is a potential therapeutic agent for prevention and treatment of sepsis-induced ALI and other inflammatory diseases.

No abstract

No abstract