Adenovirus-mediated artificial miRNA targetting fibrinogen-like protein 2 attenuates the severity of acute pancreatitis in mice

Soluble Fibrinogen-Like Protein 2 Downregulation and Th17/Treg Imbalance in a Taurocholate-Induced Murine Experimental Model of Severe Acute Pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) is associated with tremendous systemic inflammation, T-helper 17 (Th17) cells, and regulatory T (Treg) cells play an essential role in the inflammatory responses. Meanwhile, soluble fibrinogen-like protein 2 (Sfgl2) is a critical immunosuppressive effector cytokine of Treg cells and modulates immune responses. However, the impact of SAP induction on Sfgl2 expression and the role of Sfgl2 in immunomodulation under SAP conditions are largely unknown.

METHODS

A taurocholate-induced mouse SAP model was established. The ratios of CD4+CD25+Foxp3+ Treg cells or CD4+IL-17+ Th17 cells in blood and pancreatic tissues as well as surface expression of CD80, CD86, and major histocompatibility complex class II (MHC-II) were determined by flow cytometry. Gene mRNA expression was determined by qPCR. Serum amylase and soluble factors were quantitated by commercial kits. Bone marrow-derived dendritic cells (DCs) were generated, and NF-κB/p65 translocation was measured by immunofluorescence staining.

RESULTS

SAP induction in mice decreased the Th17/Treg ratio in the pancreatic tissue and increased the Th17/Treg ratio in the peripheral blood. In addition, SAP was associated with a reduced level of Sfgl2 in the pancreatic tissue and blood: higher levels of serum IL-17, IL-2, IFN-α, and TNF-α, and lower levels of serum IL-4 and IL-10. Furthermore, the SAP-induced reduction in Sfgl2 expression was accompanied by dysregulated maturation of bone marrow-derived DCs.

CONCLUSIONS

SAP causes reduced Sfgl2 expression and Th17/Treg imbalance, thus providing critical insights for the development of Sfgl2- and Th17/Treg balance-targeted immunotherapies for patients with SAP.

Circ-SFMBT2 sponges miR-224-5p to induce ketamine-induced cystitis by up-regulating metadherin (MTDH)

There is increasing evidence that circular RNAs (circRNAs) play significant roles in various biological processes, yet few reports have examined their roles and molecular mechanisms in ketamine-induced cystitis (KIC). This study examines the possible molecular mechanisms underlying the circRNA-microRNA-mRNA regulatory network in the development of KIC. Transcriptome data were collected, and bioinformatics analysis was conducted to create a circRNA-miRNA-mRNA regulatory network (ceRNA network) associated with the occurrence of KIC. Human bladder epithelial cells (SV-HUC-1) were used in in vitro cell assays. The binding affinity among circ-SFMBT2, miR-224-5p, and Metadherin (MTDH) was identified. To investigate the effects of circ-SFMBT2/miR-224-5p/MTDH on bladder function, KIC mouse models were induced by intraperitoneal injection of ketamine, and gain- or loss-of-function experiments were conducted. Our results demonstrate that MTDH may be a key gene involved in the occurrence of KIC. Both bioinformatics analysis and in vitro cell assays verified that circ-SFMBT2 can competitively bind to miR-224-5p, and miR-224-5p can target and inhibit MTDH. In the bladder tissues of KIC mice, circ-SFMBT2 and MTDH were up-regulated, while miR-224-5p was down-regulated. Animal experiments further confirmed that circ-SFMBT2 can up-regulate MTDH expression by sponging miR-224-5p, thereby exacerbating bladder dysfunction in KIC mice. This study proved that circ-SFMBT2 up-regulates MTDH by competitively binding to miR-224-5p, thereby exacerbating the bladder dysfunction of KIC.

Fibrinogen-like protein 2 in inflammatory diseases: A future therapeutic target

Fibrinogen-like protein 2 (FGL2), a member of the fibrinogen family, exists as a membrane-bound protein with immune-associated coagulation activity and a soluble form possessing immunosuppressive functions. The immunomodulatory role of FGL2 is evident in fibrin deposition-associated inflammatory diseases and cancer, suggesting that FGL2 expression could be exploited as a disease biomarker and a therapeutic target. Recently, in vitro studies and knockout and transgenic animal FGL2 models have been used by us and others to reveal the involvement of FGL2 in the pathogenesis of various inflammatory diseases. This review summarizes our current knowledge of the immunomodulatory role of FGL2 in inflammatory diseases and examines the role of FGL2 as a potential therapeutic target.

Presence and activity of Fibrinogen like protein 2 in platelets

BACKGROUND

Fibrinogen-like protein 2 (FGL2) is a serine protease capable of converting prothrombin into thrombin (i.e., prothrombinase-like activity) while bypassing the classic coagulation cascade. It has been reported to be expressed by mononuclear blood cells and endothelial cells. There are multiple reports that FGL2 supports tumor development and metastasis. However, in the blood, the origin and functional significance of FGL2 has not been established.

OBJECTIVE

To determine if FGL2, a malignancy related enzyme, is present in platelets.

METHODS

Peripheral blood samples were collected in K2 EDTA tubes. Blood cells and platelets were separated and thoroughly washed to produce plasma-free samples. Procoagulant activity was measured in the cell lysates using a thrombin generation test or an adjusted prothrombin time (PT) test in plasma deficient of factor X. The findings were further supported by confocal microscopy, immunoprecipitation, flow cytometry, enzyme-linked immunosorbent assays and specific inhibition assays.

RESULTS

FGL2 protein was readily detected in platelets. Also, despite being expressed by lymphocytes, FGL2 prothrombinase-like activity was solely detected in platelet samples, but not in white blood cell samples. Quiescent platelets were shown to contain the FGL2 protein in an active form. Upon activation, platelets secreted the active FGL2 into the milieu.

CONCLUSIONS

Active FGL2 is found in platelets. This suggests another role for the involvement of platelets in malignancies.

Potential of MicroRNAs As Biomarkers and Therapeutic Targets in Respiratory Viruses: A Literature Review

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression through recognition of cognate sequences and interference of transcriptional, translational, or epigenetic processes. Hundreds of miRNA genes have been found in diverse viruses, and many of these are phylogenetically conserved. Respiratory viruses are the most frequent causative agents of disease in humans, with a significant impact on morbidity and mortality worldwide. Recently, the role of miRNAs in respiratory viral gene regulation, as well as host gene regulation during disease progression, has become a field of interest. This review highlighted the importance of various miRNAs and their potential role in fighting with respiratory viruses as therapeutic molecules with a focus on COVID-19.

Serum soluble fibrinogen-like protein 2 concentration predicts delirium after acute pancreatitis

OBJECTIVE

Inflammation can cause delirium. Soluble fibrinogen-like protein 2 (sFGL2) is a modulator of the immune response and more recently found to be a biomarker for brain injury. This study was designed to discover the predictive capability of serum sFGL2 concentrations for delirium after acute pancreatitis (AP).

MATERIALS AND METHODS

In this prospective, observational study, serum sFGL2 concentrations were quantified in 184 healthy controls and in 184 AP patients. Disease severity was assessed by Acute Physiology and Chronic Health Care Evaluation II score, Ranson score, multiple organ dysfunction score, and sequential organ failure assessment score. Delirium was recorded during hospital stay. Predictors of delirium were identified using multivariate analysis.

RESULTS

Serum sFGL2 concentrations were substantially higher in AP patients than in controls. Serum sFGL2 concentrations were intimately correlated with the preceding severity parameters. Serum sFGL2 and the aforementioned severity parameters were independent predictors for delirium. Under receiver operating characteristic curve, the discriminatory ability of serum sFGL2 was equivalent to those of the above-mentioned severity parameters. Moreover, serum sFGL2 dramatically improved the predictive value of the aforementioned severity parameters.

CONCLUSIONS

Elevation of serum sFGL2 concentrations is strongly associated with the AP severity and has the potential to distinguish delirium after AP.