The Mechanism of Lung and Intestinal Injury in Acute Pancreatitis: A Review

Investigating key factors of feeding intolerance in severe acute pancreatitis: A scoping review

BACKGROUND

The complexity of severe acute pancreatitis (SAP) and the stress caused by the disease is associated with a high incidence of feeding intolerance. However, the factors influencing feeding incontinence in patients with SAP are diverse.

AIMS

To systematically analyse relevant studies that investigate the occurrence of feeding intolerance in patients with SAP, identify the relevant factors of feeding intolerance in such patients and provide a reference for nursing staff to develop relevant intervention measures.

DESIGN AND METHODS

This scoping review followed the approach proposed by Arksey and O'Malley. Seven electronic databases were searched from their establishment until August 2023. This included research on the factors influencing feeding intolerance in patients with SAP, determining research questions, completing literature screening and quality evaluation, extracting data and summarizing and analysing the data. The PRISMA extension for scoping reviews (PRISMA-ScR) statement has also been included.

RESULTS

A total of 23 articles were included. The factors influencing feeding intolerance in patients with SAP included the patient's condition, disease, treatment, feeding management and follow-up care.

CONCLUSIONS

The factors affecting feeding intolerance in patients with SAP are multifaceted. A personalized nursing care plan should be developed based on relevant risk factors to improve feeding tolerance and comfort in patients with SAP and shorten hospitalization time.

RELEVANCE TO CLINICAL PRACTICE

Intensive care nurses should identify the risk factors for feeding intolerance in patients with SAP and implement appropriate interventions. To identify the risk factors, nurses must be updated with courses and training. Moreover, a systematic feeding intolerance prediction program can help intensive care nurses effectively identify the risk factors for feeding.

Functional role of IL-19 in a mouse model of L-arginine-induced pancreatitis and related lung injury

IL-19 is a member of IL-10 family and is mainly produced by macrophages. Acute pancreatitis (AP) is an inflammatory disease characterized by acinar cell injury and necrosis. In the present study, the role of IL-19 in AP and AP-associated lung injury in mice was explored using L-arginine-induced pancreatitis. Experimental pancreatitis was induced by intraperitoneal injection of L-arginine in wild-type (WT) and IL-19 gene-deficient (IL-19 KO) mice. Among the mice treated with L-arginine, the serum amylase level was significantly increased in the IL-19 KO mice, and interstitial edema, analyzed using hematoxylin and eosin-stained sections, was aggravated mildly in IL-19 KO mice compared with WT mice. Furthermore, the mRNA expression of tumor necrosis factor-α was significantly upregulated in IL-19 KO mice treated with L-arginine compared with WT mice treated with L-arginine. IL-19 mRNA was equally expressed in the pancreases of both control and L-arginine-treated WT mice. The conditions of lung alveoli were then evaluated in WT and IL-19 KO mice treated with L-arginine. In mice with L-arginine-induced pancreatitis, the alveolar area was remarkedly decreased, and expression of lung myeloperoxidase was significantly increased in IL-19 KO mice compared with WT mice. In the lungs, the mRNA expression of IL-6 and inducible nitric oxide synthase was significantly increased in IL-19 KO mice compared with WT mice. In summary, IL-19 was proposed to alleviate L-arginine-induced pancreatitis by regulating TNF-α production and to protect against AP-related lung injury by inhibiting neutrophil migration.

Studies Related to the Involvement of EsA in Improving Intestinal Inflammation in Acute Pancreatitis via the NF-κB Pathway

Background

Acute pancreatitis (AP) is a clinically frequent acute abdominal condition, which refers to an inflammatory response syndrome of edema, bleeding, and even necrosis caused by abnormal activation of the pancreas's own digestive enzymes. Intestinal damage can occur early in the course of AP and is manifested by impaired intestinal mucosal barrier function, and inflammatory reactions of the intestinal mucosa, among other factors. It can cause translocation of intestinal bacteria and endotoxins, further aggravating the condition of AP. Therefore, actively protecting the intestinal mucosal barrier, controlling the progression of intestinal inflammation, and improving intestinal dynamics in the early stages of AP play an important role in enhancing the prognosis of AP.

Methods

The viability and apoptosis of RAW264.7 cells treated with Esculentoside A (EsA) and/or lipopolysaccharide were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. The expression of apoptosis-related proteins and NF-κB signaling pathway-related proteins were detected by western blot (WB). An enzyme-linked immunosorbent assay was used to measure TNF-α and IL-6 secretion.

Results

In vitro experiments demonstrated that EsA not only promoted the apoptosis of inflammatory cells but also reduced the secretion of TNF-α and IL-6 in a dose-dependent manner. Additionally, it inhibited the activation of the NF-κB signaling pathway by decreasing the expression of phosphorylated-p65(p-p65) and elevating the expression of IκBα. Similarly, in vivo experiments using a rat AP model showed that EsA inhibited the expression of p-p65 elevating the expression of IκBα in the intestinal tissues of the rat AP model and promoting the apoptosis of inflammatory cells in the intestinal mucosa in vivo experiments, while improving the pathological outcome of the pancreatic and intestinal tissues.

Conclusion

Our results suggest that EsA can reduce intestinal inflammation in the rat AP model and that EsA may be a candidate for treating intestinal inflammation in AP and further arresting AP progression.

Ameliorative Effects of Larazotide Acetate on Intestinal Permeability and Bacterial Translocation in Acute Pancreatitis Model in Rats

BACKGROUND

Intestinal barrier dysfunction in acute pancreatitis (AP) may progress to systemic inflammatory response syndrome (SIRS) and multi-organ failures by causing bacterial translocation. Larazotide acetate (LA) is a molecule that acts as a tight junction (TJ) regulator by blocking zonulin (Zo) receptors in the intestine.

AIMS

In our study, we aimed to investigate the effects of LA on intestinal barrier dysfunction and bacterial translocation in the AP model in rats.

METHODS

Thirty-two male Sprague-Dawley rats were divided into 4 groups; control, larazotide (LAR), AP, and AP + LAR. The AP model was created by administering 250 mg/100 g bm L-Arginine intraperitoneally 2 times with an hour interval. AP + LAR group received prophylactic 0.01 mg/mL LA orally for 7 days before the first dose of L-Arginine. For intestinal permeability analysis, fluorescein isothiocyanate-dextran (FITC-Dextran) was applied to rats by gavage. The positivity of any of the liver, small intestine mesentery, and spleen cultures were defined as bacterial translocation. Histopathologically damage and zonulin immunoreactivity in the intestine were investigated.

RESULTS

Compared to the control group, the intestinal damage scores, anti-Zo-1 immunoreactivity H-Score, serum FITC-Dextran levels and bacterial translocation frequency (100% versus 0%) in the AP group were significantly higher (all p < 0.01). Intestinal damage scores, anti-Zo-1 immunoreactivity H-score, serum FITC-Dextran levels, and bacterial translocation frequency (50% versus 100%) were significantly lower in the AP + LAR group compared to the AP group (all p < 0.01).

CONCLUSIONS

Our findings show that LA reduces the increased intestinal permeability and intestinal damage by its effect on Zo in the AP model in rats, and decreases the frequency of bacterial translocation as a result of these positive effects.

A bibliometric analysis of non-coding RNA studies in acute pancreatitis

BACKGROUND

Non-coding RNA (ncRNA) is a type of RNA that does not code for proteins and plays a crucial role in the onset, progression, diagnosis, and therapy of acute pancreatitis. However, bibliometric, and visual analyses of studies on acute pancreatitis and ncRNA are lacking. This study seeks to provide a bibliometric overview of the knowledge structure and research hotspots of ncRNA in the field of acute pancreatitis research.

MATERIALS AND METHODS

Literature search and collection of information in the field of ncRNA-related research in acute pancreatitis from 2000-2023 through the Web of Science Core Collection. Use CiteSpace and VOSviewer to visually analyze countries, institutions, authors, and keywords.

RESULTS

A total of 563 articles have been published in the field of ncRNA-related research in acute pancreatitis, and the number of publications in this field is gradually increasing. The largest number of publications was from China. Four clusters were produced by the co-occurrence cluster analysis of the top 89 keywords: studies of ncRNA in inflammation, autophagy, and apoptosis in acute pancreatitis; studies related to microRNA expression in pancreatic cancer among ncRNA; studies related to microRNAs as diagnostic and therapeutic markers in acute pancreatitis; and studies related to ncRNA in acute pancreatitis; The key words "injury," "pathway" and "extracellular vesicles" are the key words of emerging research hotspots.

CONCLUSION

In conclusion, ncRNA research in acute pancreatitis is an established discipline. Researchers can use the research hotspots and frontiers in this field as a guide for choosing their research direction.

Single-Cell RNA Sequencing Reveals Roles of Fibroblasts During Intestinal Injury and Repair in Rats with Severe Acute Pancreatitis

Purpose

To explore the molecular mechanisms of intestinal injury and treatment by analyzing changes in cellular heterogeneity and composition in rat ileal tissue during injury and treatment processes.

Methods

We constructed a rat model of SAP and evaluated treatment with an injected of monoacylglycerol lipase (MAGL) inhibitor (JZL184) solution using three experimental groups: healthy male Sprague-Dawley (SD) rats injected with vehicle (CON), male SD SAP model rats injected with vehicle (SAP), and male SAP rats injected with JZL184. We obtained and prepared a single-cell suspension of ileal tissue of each rat for single-cell transcriptome sequencing.

Results

This project classified changes in cellular heterogeneity and composition in rat ileal tissue during SAP-induced intestinal injury and MAGL treatment. We found that the number of fibroblast clusters was decreased in the SAP group relative to the CON group, and increased after JZL184 treatment. Further analysis of differences in gene expression between cell clusters in each group reveals that fibroblasts had the greatest number of differentially expressed genes. Most notably, expression of genes involved in communication between cells was found to vary during SAP-induced intestinal injury and JZL184 treatment. Among these changes, the degree of difference in expression of genes involved in communication between fibroblasts and other cells was the highest, indicating that fibroblasts in rat ileal tissue affect intestinal injury and repair through cell-to-cell communication. In addition, our results reveal that differentially expressed RNA-binding proteins in fibroblasts may affect their functions in intestinal injury and treatment by affecting the expression of genes regulating communication between cells.

Conclusion

These findings emphasize the importance of understanding the interactions between fibroblasts and other cells in the context of intestinal injury, providing valuable insights for further exploring molecular mechanisms and insight for discovering new treatment targets and strategies.

Adropin attenuates pancreatitis‑associated lung injury through PPARγ phosphorylation‑related macrophage polarization

Acute pancreatitis (AP)‑associated lung injury (ALI) is a critical complication of AP. Adropin is a regulatory protein of immune metabolism. The present study aimed to explore the immunomodulatory effects of adropin on AP‑ALI. For this purpose, serum samples of patients with AP were collected and the expression levels of serum adropin were detected using ELISA. Animal models of AP and adropin knockout (Adro‑KO) were constructed, and adropin expression in serum and lung tissues was investigated. The levels of fibrosis and apoptosis were evaluated using hematoxylin and eosin staining, Masson's staining and immunohistochemistry of in lung tissue. M1/M2 type macrophages in the lungs were detected using immunofluorescence staining, western blot analysis and reverse transcription‑quantitative PCR. As shown by the results, adropin expression was decreased in AP. In the Adro‑KO + L‑arginine (L‑Arg) group, macrophage infiltration, fibrosis and apoptosis were increased. The expression of peroxisome proliferator‑ activated receptor γ (PPARγ) was downregulated, and the macrophages exhibited a trend towards M1 polarization in the Adro‑KO + L‑Arg group. Adropin exogenous supplement attenuated the levels of fibrosis and apoptosis in the model of AP. Adropin exogenous supplement also increased PPARγ expression by the regulation of the phosphorylation levels, which was associated with M2 macrophage polarization. On the whole, the findings of the present study suggest that adropin promotes the M2 polarization of lung macrophages and reduces the severity of AP‑ALI by regulating the function of PPARγ through the regulation of its phosphorylation level.

Melatonin Attenuates Sepsis-Induced Acute Lung Injury via Inhibiting Excessive Mitophagy

Background

Epidemiological studies have indicated that lung injury is a frequent complication of sepsis. Mitophagy is vital to multiple pathological processes and diseases; however, its influence on sepsis-induced acute lung injury remains elusive. Melatonin has multiple antioxidant action and anti-inflammatory effects, including regulating mitophagy and inflammatory cytokine expression. Whereas, little is known about the affection of melatonin and mitophagy on CLP-induced ALI.

Methods

The in vivo effect of melatonin on OPTN-mediated mitophagy was studied by CLP-induced ALI in a mouse model using C57BL/6 followed by treatment with vehicle and melatonin (30 mg/kg/d, intraperitoneal injection). ALI was assayed by lung wet /dry ratio, hematoxylin and eosin staining, and immunohistochemical staining. Signaling pathway changes were subsequently determined by Western blotting and immunofluorescence staining. The effects of melatonin on STAT3 activation and TNF-α production were detected by Western blotting, PCR, and immunohistochemical staining.

Results

Our results indicated that OPTN, mitophagy adaptors were significantly repressed in CLP-induced ALI, accompanied by overactivation of mitophagy and inflammation. At the same time, we found that melatonin treatment alleviated ALI caused by CLP, and the effect was highly correlated with OPTN-related mitophagy. Furthermore, we demonstrated that OPTN-related mitophagy, which was normalized by melatonin, blocked STAT3 involved epithelial barrier and inflammation in vivo.

Conclusion

Overall, our results confirm that mitophagy is adjusted by melatonin in the CLP-induced ALI. Moreover, manipulation of mitophagy through melatonin could be a possible treatment to reduce sepsis-associated lung injury.

RNA-sequencing approach for exploring the protective mechanisms of dexmedetomidine on pancreatic injury in severe acute pancreatitis

Background: Severe acute pancreatitis (SAP) is a severe form of acute pancreatitis with the potential to cause life-threatening complications. Patients with acute SAP require surgical intervention and are admitted to the intensive care unit for non-invasive ventilation. Dexmedetomidine (Dex) is currently used by intensive care clinicians and anaesthesiologists as an adjunctive sedative. Therefore, the clinical availability of Dex makes it easier to implement in SAP treatment than developing new drugs. Methods: Randomly dividing thirty rats into sham-operated (Sham), SAP, and Dex groups. The severity of pancreatic tissue injury in each rat was assessed by Hematoxylin and eosin (HE) staining. Serum amylase activity and inflammatory factor levels were measured using commercially available kits. The expressions of necroptosis-related proteins, myeloperoxidase (MPO), CD68, and 4-hydroxy-trans-2-nonenal (HNE) were detected using immunohistochemistry (IHC). Transferase-mediated dUTP nick-end labeling (TUNEL) staining was utilized to identify pancreatic acinar cell apoptosis. The subcellular organelle structure of pancreatic acinar cells was observed using transmission electron microscopy. The regulatory effect of Dex on the gene expression profile of SAP rat pancreas tissue was investigated using RNA sequencing. We screened for differentially expressed genes (DEGs). Quantitative real-time PCR (qRT-PCR) measured critical DEG mRNA expression in rat pancreatic tissues. Results: Dex attenuated SAP-induced pancreatic injury, infiltration of neutrophils and macrophages, and oxidative stress. Dex inhibited the expression of necroptosis-associated proteins RIPK1, RIPK3, and MLKL and alleviated apoptosis in acinar cells. Dex also mitigated the structural damage caused by SAP to mitochondria and endoplasmic reticulum. Dex inhibited SAP-induced 473 DEGs, as determined by RNA sequencing. Dex may regulate SAP-induced inflammatory response and tissue damage by inhibiting the toll-like receptor/nuclear factor κB (TLR/NF-κB) signaling pathway and neutrophil extracellular trap formation. Conclusion: This study elucidated the remarkable effect of Dex against SAP and investigated the potential mechanism of action, providing an experimental base for the future clinical application of Dex in the treatment of SAP.

Extracellular Vesicle ITGAM and ITGB2 Mediate Severe Acute Pancreatitis-Related Acute Lung Injury

Integrins expressed on extracellular vesicles (EVs) secreted by various cancers are reported to mediate the organotropism of these EVs. Our previous experiment found that pancreatic tissue of mice with severe cases of acute pancreatitis (SAP) overexpresses several integrins and that serum EVs of these mice (SAP-EVs) can mediate acute lung injury (ALI). It is unclear if SAP-EV express integrins that can promote their accumulation in the lung to promote ALI. Here, we report that SAP-EV overexpress several integrins and that preincubation of SAP-EV with the integrin antagonist peptide HYD-1 markedly attenuates their pulmonary inflammation and disrupt the pulmonary microvascular endothelial cell (PMVEC) barrier. Further, we report that injecting SAP mice with EVs engineered to overexpress two of these integrins (ITGAM and ITGB2) can attenuate the pulmonary accumulation of pancreas-derived EVs and similarly decrease pulmonary inflammation and disruption of the endothelial cell barrier. Based on these findings, we propose that pancreatic EVs can mediate ALI in SAP patients and that this injury response could be attenuated by administering EVs that overexpress ITGAM and/or ITGB2, which is worthy of further study due to the lack of effective therapies for SAP-induced ALI.

Ferulic acid attenuates pancreaticobiliary duct occlusion-induced inflammation in both pancreas and liver

INTRODUCTION

Acute pancreatitis is a systemic inflammatory disorder characterized by the hyperactivation of digestion enzymes and the release of proinflammatory cytokines. Ferulic acid (FA) is a hydroxycinnamic acid derivative that has recently been shown to have antioxidant and anti-inflammatory properties.

AIM

The anti-inflammatory effects of FA were investigated in the pancreaticobiliary duct ligation (PBDL)-induced pancreatitis model.

METHODS

Wistar albino rats (250-300 g; female = male) were divided into sham operation and PBDL groups. Some PBDL-performed animals were given intragastric saline or 250 mg/kg FA or 500 mg/kg FA 30 min before the PBDL and for 3 consecutive days. Moreover, the control group received saline. Blood samples are collected at the 24th, 48th, and 72nd hours to measure serum tumor necrosis factor (TNF)-α, liver, and pancreatic enzymes. At the 72nd hour, rats were euthanized; pancreas, lung, and liver samples were collected, scored microscopically, and analyzed for myeloperoxidase activity, malondialdehyde, and glutathione levels. One-way ANOVA with Tukey-Kramer tests were used for statistical analysis.

RESULTS

FA treatment reduced myeloperoxidase activity and prevented the depletion of glutathione in all three tissues. With FA treatments, high malondialdehyde levels in the pancreas and liver were reduced, as were serum TNF- α, amylase, lipase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels. Additionally, FA ameliorated microscopic damage in the pancreas and liver significantly.

CONCLUSION

According to the findings, FA protects endogenous antioxidant content, prevents neutrophil infiltration, and decreases lipid peroxidation in PBDL-induced pancreatitis. Furthermore, FA improves tissue damage induced by pancreatitis with its anti-inflammatory effects.

Naringenin protects against acute pancreatitis-associated intestinal injury by inhibiting NLRP3 inflammasome activation via AhR signaling

Background: In this study, we examined the functions and mechanisms by which naringenin protects against SAP (severe acute pancreatitis)-related intestinal injury by modulating the AhR/NLRP3 signaling pathway. Material and methods: Fifteen healthy male C57BL/6 mice were randomly divided into SAP (n = 12) and normal (n = 3) groups. Mice in the SAP group received caerulein and lipopolysaccharide intraperitoneal injections and were then randomly assigned to the SAP, NAR, CH223191, and Dexamethasone (DEX) groups. Pathological changes in the pancreatic and intestinal mucosa were observed by Hematoxylin & Eosin (H&E) staining. In vitro, RAW264.7 cells were exposed to lipopolysaccharide and treated with naringenin. The levels of NLRP3, AhR, IL-1β, TNF, and IL-6 in the SAP model and RAW264.7 cells were evaluated by enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (qRT-PCR), western blot, and immunohistochemistry. The nuclear translocation of AhR was shown by immunofluorescence. AutoDockTools was used to predict the conformations of naringenin-AhR binding, and PyMol 2.4 was used to visualize the conformations. Results: Mouse pancreatic and intestinal injury was alleviated by treatment with naringenin. Naringenin inhibited the activation of the NLRP3 inflammasome and inhibited damage to intestinal tight junctions. Moreover, naringenin increased AhR nuclear translocation and activated the AhR pathway. Conclusion: Naringenin can reduce SAP-associated intestinal injury by inhibiting the activation of the NLRP3 inflammasome via the AhR signaling pathway.

Hemorheological and Microcirculatory Relations of Acute Pancreatitis

Acute pancreatitis still means a serious challenge in clinical practice. Its pathomechanism is complex and has yet to be fully elucidated. Rheological properties of blood play an important role in tissue perfusion and show non-specific changes in acute pancreatitis. An increase in blood and plasma viscosity, impairment of red blood cell deformability, and enhanced red blood cell aggregation caused by metabolic, inflammatory, free radical-related changes and mechanical stress contribute to the deterioration of the blood flow in the large vessels and also in the microcirculation. Revealing the significance of these changes in acute pancreatitis may better explain the pathogenesis and optimize the therapy. In this review, we give an overview of the role of impaired microcirculation by changes in hemorheological properties in acute pancreatitis.

Hydrogen Sulfide: A Gaseous Mediator and Its Key Role in Programmed Cell Death, Oxidative Stress, Inflammation and Pulmonary Disease

Hydrogen sulfide (H₂S) has been acknowledged as a novel gaseous mediator. The metabolism of H₂S in mammals is tightly controlled and is mainly achieved by many physiological reactions catalyzed by a suite of enzymes. Although the precise actions of H₂S in regulating programmed cell death, oxidative stress and inflammation are yet to be fully understood, it is becoming increasingly clear that H₂S is extensively involved in these crucial processes. Since programmed cell death, oxidative stress and inflammation have been demonstrated as three important mechanisms participating in the pathogenesis of various pulmonary diseases, it can be inferred that aberrant H₂S metabolism also functions as a critical contributor to pulmonary diseases, which has also been extensively investigated. In the meantime, substantial attention has been paid to developing therapeutic approaches targeting H₂S for pulmonary diseases. In this review, we summarize the cutting-edge knowledge on the metabolism of H₂S and the relevance of H₂S to programmed cell death, oxidative stress and inflammation. We also provide an update on the crucial roles played by H₂S in the pathogenesis of several pulmonary diseases. Finally, we discuss the perspective on targeting H₂S metabolism in the treatment of pulmonary diseases.

Fighting Fire with Fire: Exosomes and Acute Pancreatitis-Associated Acute Lung Injury

Acute pancreatitis (AP) is a prevalent clinical condition of the digestive system, with a growing frequency each year. Approximately 20% of patients suffer from severe acute pancreatitis (SAP) with local consequences and multi-organ failure, putting a significant strain on patients' health insurance. According to reports, the lungs are particularly susceptible to SAP. Acute respiratory distress syndrome, a severe type of acute lung injury (ALI), is the primary cause of mortality among AP patients. Controlling the mortality associated with SAP requires an understanding of the etiology of AP-associated ALI, the discovery of biomarkers for the early detection of ALI, and the identification of potentially effective drug treatments. Exosomes are a class of extracellular vesicles with a diameter of 30-150 nm that are actively released into tissue fluids to mediate biological functions. Exosomes are laden with bioactive cargo, such as lipids, proteins, DNA, and RNA. During the initial stages of AP, acinar cell-derived exosomes suppress forkhead box protein O1 expression, resulting in M1 macrophage polarization. Similarly, macrophage-derived exosomes activate inflammatory pathways within endothelium or epithelial cells, promoting an inflammatory cascade response. On the other hand, a part of exosome cargo performs tissue repair and anti-inflammatory actions and inhibits the cytokine storm during AP. Other reviews have detailed the function of exosomes in the development of AP, chronic pancreatitis, and autoimmune pancreatitis. The discoveries involving exosomes at the intersection of AP and acute lung injury (ALI) are reviewed here. Furthermore, we discuss the therapeutic potential of exosomes in AP and associated ALI. With the continuous improvement of technological tools, the research on exosomes has gradually shifted from basic to clinical applications. Several exosome-specific non-coding RNAs and proteins can be used as novel molecular markers to assist in the diagnosis and prognosis of AP and associated ALI.