Irisin inhibits neutrophil extracellular traps formation and protects against acute pancreatitis in mice

INTRODUCTION

Irisin is a newly discovered myokine which links exercise to inflammation and inflammation-related diseases through macrophage regulation. However, the effect of irisin on the activity of inflammation related immune cells (such as neutrophils) has not been clearly described.

OBJECTIVES

The objective of our study was to explore the effect of irisin on the neutrophil extracellular traps (NETs) formation.

METHODS

Phorbol-12-myristate-13-acetate (PMA) was used to construct a classic neutrophil inflammation model that was used to observe the formation of NETs in vitro. We studied the effect of irisin on NETs formation and its regulation mechanism. Subsequently, acute pancreatitis (AP) was used to verify the protective effect of irisin in vivo, which was an acute aseptic inflammatory response disease model closely related to NETs.

RESULTS

Our study found that addition of irisin significantly reduced the formation of NETs via regulation of the P38/MAPK pathway through integrin αVβ5, which might be the one of key pathways in NETs formation, and which could theoretically offset the immunoregulatory effect of irisin. Systemic treatment with irisin reduced the severity of tissue damage common in the disease and inhibited the formation of NETs in pancreatic necrotic tissue of two classical AP mouse models.

CONCLUSION

The findings confirmed for the first time that irisin could inhibit NETs formation and protect mice from pancreatic injury, which further elucidated the protective effect of exercise on acute inflammatory injury.

Elevated serum HbA1c level, rather than previous history of diabetes, predicts the disease severity and clinical outcomes of acute pancreatitis

INTRODUCTION

The aim of our study is to explore the value of serum glycosylated hemoglobin A1c (HbA1c) in disease severity and clinical outcomes of acute pancreatitis (AP).

RESEARCH DESIGN AND METHODS

Patients with AP were included from January 2013 to December 2020, retrospectively, dividing into normal serum HbA1c level (N-HbA1c) group and high serum HbA1c level (H-HbA1c) group according to the criteria HbA1c <6.5%. We compared patient characteristics, biochemical parameters, disease severity, and clinical outcomes of patients with AP in two groups. Besides, we evaluated the efficacy of serum HbA1c to predict organ failure (OF) in AP patients by receiver operating curve (ROC).

RESULTS

We included 441 patients with AP, including 247 patients in N-HbA1c group and 194 patients in H-HbA1c group. Serum HbA1c level was positively correlated with Atlanta classification, systemic inflammatory response syndrome, local complication, and OF (all p<0.05). Ranson, BISAP (bedside index of severity in acute pancreatitis), and CT severity index scores in patients with H-HbA1c were markedly higher than those in patients with N-HbA1c (all p<0.01). ROC showed that the best critical point for predicting the development of OF in AP with serum HbA1c is 7.05% (area under the ROC curve=0.79). Logistic regression analysis showed H-HbA1c was the independent risk factor for the development of OF in AP. Interestingly, in patients with presence history of diabetes and HbA1c <6.5%, the severity of AP was significantly lower than that in H-HbA1c group. Besides, there was no significant difference between with and without history of diabetes in N-HbA1c group.

CONCLUSIONS

Generally known, diabetes is closely related to the development of AP, and strict control of blood glucose can improve the related complications. Thus, the level of glycemic control before the onset of AP (HbA1c as an indicator) is the key to poor prognosis of AP, rather than basic history of diabetes. Elevated serum HbA1c level can become the potential indicator for predicting the disease severity of AP.

Elevated serum ferritin levels are associated with severity and prognosis of severe acute pancreatitis: a preliminary cohort study

Background

Serum ferritin (SF), as an acute-phase response protein, is used to reflect the degree of oxidative stress and systemic inflammatory responses. This study was designed to assess the effect of elevated SF levels on the severity of acute pancreatitis (AP).

Methods

From January 2013 to December 2020, 200 consecutive patients with AP were retrospectively reviewed to analyze the relationships among the etiologies of pancreatitis, the severity of the disease and SF levels. The receiver operating characteristic (ROC) curve and logistic regression analysis were used to assess whether elevated SF levels could predict the onset of organ failure in AP.

Results

92 (46%) had high SF levels (> 275 ng/ml). SF levels were not associated with the etiology of AP disease. Among patients with high SF levels, there was a significant increase in the proportion of patients with severe AP (23.1% vs. 76.9%) and a higher proportion of systemic inflammatory response scores (25.9% vs. 44.6%) in comparison to patients with normal SF levels. The area under the ROC curve for SF in predicting persistent organ failure was 0.812 [95% confidence interval 0.721–0.904].

Conclusions

F concentrations were positively correlated with the severity of AP, and quantitative assessment of SF can predict disease severity and organ failure in patients with AP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02446-z.

Isoliquiritigenin ameliorates doxorubicin-induced acute pancreatitis by inhibiting ROS production via modulation of Nrf2/HO-1 oxidative stress pathway

BACKGROUND

Several case studies have reported that doxorubicin (DOX) could induce acute pancreatitis, but no animal experiments have confirmed such side effect of DOX, and there is no specific treatment. Isoliquiritigenin (ISL) has a variety of pharmacological functions, including anti-inflammatory and antioxidant activities; however, the role and mechanism of ISL on DOX-induced acute pancreatitis (DAP) remain unclear.

AIM

To confirm whether doxorubicin (DOX) results in pancreatic tissue injury, and to determine the role and mechanism of isoliquiritigenin (ISL) in protecting against DOX-induced pancreatitis.

METHODS

Male ICR mice (25-30 g) were randomly divided into a control group (intraperitoneal injection of normal saline), DOX-DAP model group (intraperitoneal injection of DOX 10 mg/kg every other day), and ISL treatment group (DOX + ISL group; intraperitoneal injection of DOX 10 mg/kg every other day and intragastric administration of ISL 100 mg/kg per day), with 8 mice in each group. Pancreatic histopathology and scoring were performed 5 d after modeling. The expression of alpha amylase in pancreatic tissue was detected by immunohistochemistry. Immunofluorescence assay was used to detect ROS production in pancreatic tissue. Protein expression of Nrf2 and HO-1 in pancreatic tissue was detected by Western blot.

RESULTS

Compared with the control group, the mice in the DOX-DAP model group showed characteristic pathological damage, such as pancreatic tissue edema and inflammatory cells infiltration, with significantly increased histopathological scores (P < 0.001) and decreased expression of alpha amylase in the pancreas (P < 0.01). Compared with the DOX-DAP model group, the DOX + ISL group had significantly decreased histopathological scores (P < 0.05) and increased expression of alpha amylase in the pancreas (P < 0.05). ROS fluorescence staining and Western blot analysis showed that compared with the control group, ROS generation in pancreatic tissue in the DOX-DAP model group was significantly increased (P < 0.001), and the expression levels of Nrf2 and HO-1 proteins were slightly increased (P < 0.001). Compared with the DOX-DAP group, the DOX + ISL group had significantly decreased ROS levels in pancreatic tissuesed (P < 0.001), and significantly increased expression of Nrf2 and HO-1 proteins (P < 0.001).

CONCLUSION

DOX can cause pancreatic pathological damage in mice, which is mainly characterized by pancreatic tissue edema and inflammatory cells infiltration. ISL administration has a protective effect on DOX-induced pancreatitis by enhancing the antioxidant stress level in pancreatic tissue, which is expected to provide a new method for the prevention and treatment of drug-induced pancreatitis.

[Clinical study on early loading restoration of superhydrophilic implants]

Objective: To study the clinical effect of early loading restoration a superhydrophilic implant after 1 year, so as to provide reference evidence for clinical practice. Methods: A total of 41 patients with dental defects, including 20 males and 21 females [age (52.3±13.1) years old], were enrolled in the Department of VIP, Hangzhou Dental Hospital (Pinghai Hospital) from July 2017 to January 2019. A total of 74 superhydrophilic implants were implanted, including 27 maxillary implants and 47 mandiolar implants. All patients without bone augmentation or soft tissue transplantation, the maxilla was taken impression 4 weeks after implant implantation, with 6 weeks of loading, the mandible was taken impression 2 weeks after implant implantation, with 4 weeks of loading. The stability of the implant was measured by resonance frequency analyzer before implant implantation, impression and loading. Periapical radiograph were taken immediately after mold removal, immediately after loading and reexamination 1 year after loading, to measure and record the changes in the bone level of the mesial and distal margins of the implant. Results: No biological complications occurred in all implants before loading restoration, and the implant survival rate was 100%(74/74). In 2 cases, the implant stability quotient (ISQ) value of the implant at the mandibular site was lower than 65 at 2 weeks after surgery, and the restoration was delayed. The ISQ values of the other 72 implants at the time of implantation (75.22±4.32) were not significantly different from those at the time of modeling (75.13±4.23) (P>0.05), but the ISQ values at the moment of weight loading (76.46±3.73) were significantly higher than those at modeling (P<0.05). All the early loading implants were reviewed 1 year after early loading, and none of them were loose or fell off, and the implant survival rate was 100%(72/72). X-ray measurement and evaluation showed that after 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.18±0.06) mm, among which the mandibular was (0.17±0.06) mm and the maxillary was (0.19±0.06) mm, showing no statistical difference (P>0.05). After 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.17±0.05) mm, including (0.17±0.06) mm for mandibular and (0.16±0.05) mm for maxillary, showing no statistical difference (P>0.05). Conclusions: In the limited scope of this clinical study, it has been proved that early loading of superhydrophilic implant is a safe and feasible treatment scheme, and the bone resorption at the implant edge after long-term early loading restoration needs further follow-up study.

[Advance in study of artificial nerve]

OBJECTIVE

To review the advance in materials of nerve conduit and Schwann cell transplantation for preparation of artificial nerve with tissue engineering technique.

METHODS

Recent literatures about artificial nerve, nerve conduit and Schwann cell transplantation were extensively reviewed.

RESULTS

Many biomaterials such as silicon, dacron, expanded polytetrafluoroethylene(ePTFE), polyester and chitin could be used as nerve conduits to repair nerve defect, the degradable biomaterials were better. The nerve conduit with intrinsic filaments could be used to bridge an extended gap in peripheral nerve. Purified and cultured Schwann cells were still bioactive. Axonal regeneration could be enhanced after implantation of Schwann cells into nerve conduit.

CONCLUSION

The ideal artificial nerve is composed of three dimensional biodegradable nerve conduit and bioactive Schwann cells, Schwann cells can be distributed in nerve conduit just like Bünger's band.