Sitagliptin activates the p62-Keap1-Nrf2 signalling pathway to alleviate oxidative stress and excessive autophagy in severe acute pancreatitis-related acute lung injury

Exposure to salinomycin dysregulates interplay between mitophagy and oxidative response to damage the porcine jejunal cells

Salinomycin (SAL) has caused widespread pollution as a feed additive and growth promoter in livestock such as pigs, exerting a negative impact on public health. The toxicity mechanism of SAL has been widely studied in chickens, but the underlying mechanisms of SAL-induced toxicity to pigs and the ecosystem remain undefined. In this study, we explored the potential damage of SAL in IPEC-J2 cells to identify the effects of excessive SAL on the interplay between mitophagy and oxidative stress. The results showed that a concentration-dependent response was observed for SAL in altering cellular morphology and inducing cell death in IPEC-J2 cells, including the induction of cell cycle arrest and lactic dehydrogenase (LDH) release. Meanwhile, we found that excessive SAL led to oxidative damage by activating the Nrf2/Keap1/HO-1 pathway, accompanied by reactive oxygen species (ROS) elevation and the reduction of antioxidant enzyme activity. We also found that PINK1/Parkin-dependent mitophagy was activated by SAL exposure, particularly with mitochondrial membrane potential reduction. Interestingly, SAL-induced oxidative damages were prevented after the autophagy inhibitor 3-methyladenine (3-MA) treatment, and mitophagy was alleviated following ROS scavenger (N-acetylcysteine, NAC) treatment. Overall, our findings showed that SAL stimulated oxidative stress and mitophagy in IPEC-J2 cells resulting in cellular injury, and there was a strong connection between SAL-induced oxidative stress and mitophagy. Targeting ROS/PINK1/Parkin-dependent mitophagy and oxidative stress could be a novel protective mechanism in SAL-induced cell damage.

Cyasterone ameliorates sepsis-related acute lung injury via AKT (Ser473)/GSK3β (Ser9)/Nrf2 pathway

BACKGROUND

Acute lung injury (ALI) is a severe disease that can lead to acute respiratory distress syndrome (ARDS), characterized by intractable hypoxemia, poor lung compliance, and respiratory failure, severely affecting patients' quality of life. The pathogenesis of ALI has not been fully elucidated yet, and sepsis is an important cause of ALI. Among the organ injuries caused by sepsis, the lungs are the earliest damaged ones. Radix cyathulae is reported to have analgesic, anti-inflammatory, and anti-aging effects. Cyasterone is extracted from Radix cyathulae. However, it is not known whether cyasterone has protective effects for ALI. This study aims to investigate the effect of cyasterone on sepsis-related ALI and its mechanism.

METHODS

We used the cecal ligation peferation (CLP) method to establish a mouse sepsis model, and cyasterone was given intraperitoneally on days 1-3 to observe its preventive effect on sepsis-related acute lung injury. Primary murine peritoneal macrophages were used to investigate the molecular mechanism of cyasterone in vitro.

RESULTS

Cyasterone pretreatment inhibits pro-inflammatory cytokine production, NLRP3 inflammasome activation, and oxidative stress in vivo and in vitro. In addition, cyasterone attenuates sepsis-induced ALI by activating nuclear factor erythroid2-related factor (Nrf2), which may be associated with AKT(Ser473)/GSK3β(Ser9) pathway activation.

CONCLUSIONS

Cyasterone defends against sepsis-induced ALI by inhibiting inflammatory responses and oxidative stress, which depends heavily on the upregulation of the Nrf2 pathway through phosphorylation of AKT(Ser473)/GSK3β(Ser9). These results suggest cyasterone may be a valuable drug candidate for preventing sepsis-related ALI.

Activation of the p62-Keap1-Nrf2 pathway protects against oxidative stress and excessive autophagy in ovarian granulosa cells to attenuate DEHP-induced ovarian impairment in mice

Di-(2-ethylhexyl) phthalate (DEHP) is widely used in various plastics but has been demonstrated to cause female reproductive toxicity. However, the exact mechanism underlying the ovarian damage induced by DEHP remains unclear. In this study, DEHP was administered orally to 5-week-old female mice for 30 days at doses of 0, 250, 500, and 1000 mg/kg/day. The findings demonstrated that DEHP exposure disrupted ovarian function and follicular development as well as induced oxidative stress and autophagy in ovarian granulosa cells (GCs). Further, 200 µM mono-(2-ethylhexyl) phthalate (MEHP), the primary metabolite of DEHP in vivo, induced autophagy in both human ovarian granulosa cells line (KGN) and mouse primary GCs within 24 h in vitro. However, it did not affect the p62-dependent autophagy flux. Furthermore, MEHP-induced autophagy was inhibited by the autophagy inhibitor 3-MA and exacerbated by the autophagy activator rapamycin, indicating that MEHP induces excessive autophagy in GCs. Subsequently, we found that MEHP-induced autophagic cell death was primarily attributed to oxidative damage from elevated intracellular ROS levels. Meanwhile, MEHP exposure induced nuclear translocation of erythroid-derived factor 2-related factor (Nrf2), a key regulator of antioxidant activity resulting in activating antioxidant effects. Interestingly, we also found that MEHP-induced increase in p62 competitively binds Keap1, thereby facilitating nuclear translocation of Nrf2 and establishing a positive feedback loop in antioxidant regulation. Therefore, this study demonstrated that inhibition of Nrf2 could aggravate oxidative damage and enhance excessive autophagy caused by MEHP, while activation of Nrf2 could reverse the trend. These findings have also been reinforced in studies of cultured ovaries in vitro. Our study suggests that the p62-Keap1-Nrf2 pathway may serve as a potential protective mechanism against DEHP-induced oxidative stress and excessive autophagy in mouse GCs.

An in-Depth Exploration of the Genetic Interaction Network Between Ferroptosis and Acute Pancreatitis

Background

Ferroptosis plays an important role in a variety of disease processes and is equally important in pancreatic diseases. However, the role of ferroptosis-related genes (FRGs) in acute pancreatitis (AP) remains unknown, and their specific potential mechanisms still need to be explored extensively.

Methods

AP-related gene microarray data were obtained from the GEO database, while FRGs were obtained from the ferroptosis database (FerrDb). Differentially expressed genes (DEGs) were screened by the "limma" package, and GSEA was performed. The corresponding ferroptosis-related differentially expressed genes (FRDEGs) were screened, and GO and KEGG pathway analyses were performed. A PPI network was constructed to identify hub FRDEGs by CytoHubba, MCODE and CTD scores. Transcription factors and miRNAs predicted using the NetworkAnalyst database were used to establish the regulatory network. Immune cell infiltration analysis was performed by the R package "ssGSEA" algorithm. The hub genes were validated by transcriptome sequencing of AP model mice and immunohistochemistry in rats and mice.

Results

A total of 82 FRDEGs were screened, and these genes were mainly associated with ferroptosis, hypoxic response, autophagy, mitophagy and immune inflammation. However, we also found that these genes are also jointly involved in other cell death modalities, such as apoptosis and necroptosis. Further analysis obtained 7 hub genes from 82 genes, and single-sample gene set enrichment analysis (ssGSEA) showed that the hub genes are closely associated with the infiltration of specific immune cells and the activation of immune pathways.

Conclusion

This study reveals the complex functions and important roles of ferroptosis-related genes in AP and provides gene targets for further studies of AP.

Paraquat-induced ferroptosis suppression via NRF2 expression regulation

Paraquat (PQ) is an environmentally friendly and efficient herbicide, but PQ misuse or intentional self-use can cause death through multiple organ damage and can cause acute lung injury. Existing clinical treatments alleviate symptoms but do not significantly improve the mortality rate. Ferroptosis is a type of necrosis that presents in a manner very similar to the cell damage induced by high doses of PQ, but the role of ferroptosis in paraquat-induced lung injury remains unclear. In this study, we aimed to explore the role of ferroptosis in PQ-induced A549 cell injury and identify the potential mechanisms and critical sites of protection against PQ-induced A549 injury by ferroptosis inhibitors. We found that the ferroptosis inhibitors Ferr-1 and Lip-1 inhibit ferroptosis by attenuating oxidative stress through the upregulation of NRF2 gene expression. The protective role of the ferroptosis inhibitor Dfo was most evident in paraquat-induced cell injury. Dfo inhibited ferroptosis by iron chelation and promoted NRF2 protein level reduction. NRF2 attenuated PQ-induced ferroptosis in A549 cells, mainly through the upregulation of SLC40A1 to encourage the movement of iron to the extracellular side to alleviate iron overload, and the upregulation of SLC7A11 to promote the expression of GPX4 to inhibit lipid peroxidation.

Integration of transcriptomics reveals ferroptosis-related signatures and immune cell infiltration in bronchopulmonary dysplasia

Ferroptosis has emerged as a significant factor in the development of bronchopulmonary dysplasia (BPD). Nevertheless, our understanding of the potential involvement of ferroptosis-related genes (FRGs) in BPD remains incomplete. In this study, we leveraged the Gene Expression Omnibus (GEO) database to investigate this aspect. We identified 20 differentially expressed FRGs that are associated with BPD, shedding light on their potential role in the condition.LASSO along with SVM-RFE algorithms found that 12 genes: MEG3, ACSL1, DPP4, GALNT14, MAPK14, CD82, SMPD1, NR1D1, PARP3, ACVR1B, H19, and SLC7A11 were closely related to ferroptosis modulation and immunological response. These genes were used to create a nomogram with good predictive power and were found to be involved in BPD-linked pathways. In addition, the marker genes-based prediction model performed well in external validation data sets. The study also showed a significance between BPD and control samples in terms of immune cell infiltration. These findings may help improve our understanding of FRGs in BPD and lead to the development of more effective immunotherapies.

The Role and Potential Regulatory Mechanism of STING Modulated Macrophage Apoptosis and Differentiation in Severe Acute Pancreatitis-Associated Lung Injury

This study aims to investigate the role of STING in promoting macrophage apoptosis and regulating macrophage polarization in severe acute pancreatitis (SAP)-associated lung injury in vitro and in vivo. A murine model was established by intraperitoneal injection of caerulein and lipopolysaccharide (LPS). Meanwhile, ANA-1 cells were stimulated with LPS to induce apoptosis in vitro. More primary alveolar macrophages underwent apoptosis and M1 macrophage polarization in the SAP group compared with the control group, which was reversed by inhibiting STING. When ANA-1 cells were induced into M2-type macrophages, the reduction of M1 macrophage markers was accompanied by a decrease of LPS-induced apoptosis. Finally, the inhibitory effect of C-176 on STING ameliorates lung injury and inflammation by adjusting macrophage polarization and rescuing apoptosis. Therefore, inhibiting STING could be a new therapeutic strategy for treating acute pancreatitis-associated lung injury.

Zerumbone ameliorates the inflammatory response and organ damage in severe acute pancreatitis via the ROS/NF-κB pathway

OBJECTIVE

The aim of the current study was to determine the mechanism by which Zerumbone (ZER) ameliorates inflammation and organ damage in a rat model of severe acute pancreatitis (SAP).

METHODS

Different concentrations of ZER (10, 20 and 40 mg/kg) were administered by femoral vein puncture 30 min prior to establishment of the SAP model. Hematoxylin and eosin (H&E) staining was used to assess pathological changes in the pancreatic tissue of SAP-induced rats. The lung wet/dry (W/D) ratio was assessed and serum levels of amylase (AMY), alanine aminotransferase (ALT), creatinine (Cr), aspartate aminotransferase (AST) and phospholipase A2 (PLA2) were measured. Western blot analysis was used to examine changes in the expression of ROS/NF-κB pathway-associated proteins.

RESULTS

SAP was confirmed by significant histopathological damage to the pancreas. ZER (10, 20 and 40 mg/kg) was found to alleviate pancreatitis and decrease ascites volume, lung W/D ratio, pancreatic pathology score, oxidative stress and inflammatory damage. High concentrations (20 and 40 mg/kg) of ZER were shown to increase levels of hepatorenal toxicity. In contrast, 10 mg/kg ZER was found to attenuate liver enzyme levels, reduce pathological damage to the liver, and protect against extrapancreatic organ damage to the liver in SAP-induced rats. Moreover, ZER showed no significant side effects in normal rats. Finally, we demonstrated that ZER mediated its anti-inflammatory effects on SAP through the ROS/NF-κB signaling pathway.

CONCLUSION

ZER alleviated SAP-induced oxidative stress and inflammatory injury via the ROS/NF-κB pathway, and had a protective effect on lung injury and liver damage.

Targeting ferroptosis opens new avenues for the development of novel therapeutics

Ferroptosis is an iron-dependent form of regulated cell death with distinct characteristics, including altered iron homeostasis, reduced defense against oxidative stress, and abnormal lipid peroxidation. Recent studies have provided compelling evidence supporting the notion that ferroptosis plays a key pathogenic role in many diseases such as various cancer types, neurodegenerative disease, diseases involving tissue and/or organ injury, and inflammatory and infectious diseases. Although the precise regulatory networks that underlie ferroptosis are largely unknown, particularly with respect to the initiation and progression of various diseases, ferroptosis is recognized as a bona fide target for the further development of treatment and prevention strategies. Over the past decade, considerable progress has been made in developing pharmacological agonists and antagonists for the treatment of these ferroptosis-related conditions. Here, we provide a detailed overview of our current knowledge regarding ferroptosis, its pathological roles, and its regulation during disease progression. Focusing on the use of chemical tools that target ferroptosis in preclinical studies, we also summarize recent advances in targeting ferroptosis across the growing spectrum of ferroptosis-associated pathogenic conditions. Finally, we discuss new challenges and opportunities for targeting ferroptosis as a potential strategy for treating ferroptosis-related diseases.

SQSTM1 is a therapeutic target for infection and sterile inflammation

Inflammation represents a fundamental immune response triggered by various detrimental stimuli, such as infections, tissue damage, toxins, and foreign substances. Protein degradation plays a crucial role in regulating the inflammatory process at multiple levels. The identification of sequestosome 1 (SQSTM1, also known as p62) protein as a binding partner of lymphocyte-specific protein tyrosine kinase in 1995 marked a significant milestone. Subsequent investigations unveiled the activity of SQSTM1 to interact with diverse unstructured substrates, including proteins, organelles, and pathogens, facilitating their delivery to the lysosome for autophagic degradation. In addition to its well-established intracellular functions, emerging studies have reported the active secretion or passive release of SQSTM1 by immune or non-immune cells, orchestrating the inflammatory responses. These distinct characteristics render SQSTM1 a critical therapeutic target in numerous human diseases, including infectious diseases, rheumatoid arthritis, inflammatory bowel disease, pancreatitis, asthma, chronic obstructive pulmonary disease, and cardiovascular diseases. This review provides a comprehensive overview of the structure and modulation of SQSTM1, discusses its intracellular and extracellular roles in inflammation, and highlights its significance in inflammation-related diseases. Future investigations focusing on elucidating the precise localization, structure, post-translational modifications of SQSTM1, as well as the identification of additional interacting partners, hold promise for unravelling further insights into the multifaceted functions of SQSTM1.

The therapeutic potential for targeting CSE/H2S signaling in macrophages against Escherichia coli infection

Macrophages play a pivotal role in the inflammatory response to the zoonotic pathogen E. coli, responsible for causing enteric infections. While considerable research has been conducted to comprehend the pathogenesis of this disease, scant attention devoted to host-derived H2S. Herein, we reported that E. coli infection enhanced the expression of CSE in macrophages, accompanied by a significantly increased inflammatory response. This process may be mediated by the involvement of excessive autophagy. Inhibition of AMPK or autophagy with pharmacological inhibitors could alleviate the inflammation. Additionally, cell model showed that the mRNA expression of classic inflammatory factors (Il-1β, Il-6), macrophage polarization markers (iNOS, Arg1) and ROS production was significantly down-regulated after employing CSE specific inhibitor PAG. And PAG is capable of inhibiting excessive autophagy through the LKB1-AMPK-ULK1 axis. Interestingly, exogenous H2S could suppress inflammation response. Our study emphasizes the importance of CSE in regulating the macrophage-mediated response to E. coli. Increased CSE in macrophages leads to excessive inflammation, which should be considered a new target for drug development to treat intestinal infection.

Exosomes from TNF-α preconditioned human umbilical cord mesenchymal stromal cells inhibit the autophagy of acinar cells of severe acute pancreatitis via shuttling bioactive metabolites

Severe acute pancreatitis (SAP) is a common critical disease of the digestive system, with high mortality and a lack of effective prevention and treatment measures. Despite mesenchymal stromal cell transplantation having the potential to treat SAP, its clinical application prospect is limited, and the mechanism is unclear. Here, we reveal the therapeutic role of exosomes from TNF-α-preconditioned human umbilical cord mesenchymal stromal cells (HUCMSCs) in attenuating SAP and show that it is partly dependent on exosomal metabolites. Bioactive metabolomics analysis showed that 48 metabolites be significantly differentially expressed between the two groups (Exo-Ctrl group versus Exo-TNF-α group). Then, the further functional experiments indicated that 3,4-dihydroxyphenylglycol could be a key molecule mediating the therapeutic effect of TNF-α-preconditioned HUCMSCs. The animal experiments showed that 3,4-dihydroxyphenylglycol reduced inflammation and oxidative stress in the pancreatic tissue and inhibited acinar cell autophagy in a rat model of SAP. Mechanistically, we revealed that 3,4-dihydroxyphenylglycol activated the mTOR pathway to inhibit acinar cell autophagy and alleviate SAP. In summary, our study demonstrated that exosomes from TNF-α-preconditioned HUMSCs inhibit the autophagy of acinar cells of SAP by shuttling 3,4-dihydroxyphenylglycol and inhibiting the mTOR pathway. This study revealed the vital role and therapeutic potential of metabolite-derived exosomes in SAP, providing a new promising method to prevent and therapy SAP.

Mechanisms of Qingyi Decoction in Severe Acute Pancreatitis-Associated Acute Lung Injury via Gut Microbiota: Targeting the Short-Chain Fatty Acids-Mediated AMPK/NF-κB/NLRP3 Pathway

The pivotal roles of gut microbiota in severe acute pancreatitis-associated acute lung injury (SAP-ALI) are increasingly revealed, and recent discoveries in the gut-lung axis have provided potential approaches for treating SAP-ALI. Qingyi decoction (QYD), a traditional Chinese medicine (TCM), is commonly used in clinical to treat SAP-ALI. However, the underlying mechanisms remain to be fully elucidated. Herein, by using a caerulein plus lipopolysaccharide (LPS)-induced SAP-ALI mice model and antibiotics (Abx) cocktail-induced pseudogermfree mice model, we tried to uncover the roles of the gut microbiota by administration of QYD and explored its possible mechanisms. Immunohistochemical results showed that the severity of SAP-ALI and intestinal barrier functions could be affected by the relative depletion of intestinal bacteria. The composition of gut microbiota was partially recovered after QYD treatment with decreased Firmicutes/Bacteroidetes ratio and increased relative abundance in short-chain fatty acids (SCFAs)-producing bacteria. Correspondingly increased levels of SCFAs (especially propionate and butyrate) in feces, gut, serum, and lungs were observed, generally consistent with changes in microbes. Western-blot analysis and RT-qPCR results indicated that the AMPK/NF-κB/NLRP3 signaling pathway was activated after oral administration of QYD, which was found to be possibly related to the regulatory effects on SCFAs in the intestine and lungs. In conclusion, our study provides new insights into treating SAP-ALI through modulating the gut microbiota and has prospective practical value for clinical use in the future. IMPORTANCE Gut microbiota affects the severity of SAP-ALI and intestinal barrier function. During SAP, a significant increase in the relative abundance of gut pathogens (Escherichia, Enterococcus, Enterobacter, Peptostreptococcus, Helicobacter) was observed. At the same time, QYD treatment decreased pathogenic bacteria and increased the relative abundance of SCFAs-producing bacteria (Bacteroides, Roseburia, Parabacteroides, Prevotella, Akkermansia). In addition, The AMPK/NF-κB/NLRP3 pathway mediated by SCFAs along the gut-lung axis may play an essential role in preventing the pathogenesis of SAP-ALI, which allows for reduced systemic inflammation and restoration of the intestinal barrier.

Cellular senescence in liver diseases: From mechanisms to therapies

Cellular senescence is an irreversible state of cell cycle arrest, characterized by a gradual decline in cell proliferation, differentiation, and biological functions. Cellular senescence is double-edged for that it can provoke organ repair and regeneration in physiological conditions but contribute to organ and tissue dysfunction and prime multiple chronic diseases in pathological conditions. The liver has a strong regenerative capacity, where cellular senescence and regeneration are closely involved. Herein, this review firstly introduces the morphological manifestations of senescent cells, the major regulators (p53, p21, and p16), and the core pathophysiologic mechanisms underlying senescence process, and then specifically generalizes the role and interventions of cellular senescence in multiple liver diseases, including alcoholic liver disease, nonalcoholic fatty liver disease, liver fibrosis, and hepatocellular carcinoma. In conclusion, this review focuses on interpreting the importance of cellular senescence in liver diseases and summarizes potential senescence-related regulatory targets, aiming to provide new insights for further researches on cellular senescence regulation and therapeutic developments for liver diseases.

Sitagliptin inhibits the survival, stemness and autophagy of glioma cells, and enhances temozolomide cytotoxicity

The standard regimen treatment has improved GBM outcomes, but the survival rate of patients is still unsatisfactory. Temozolomide (TMZ) resistance is one of main reasons limiting the therapeutic efficacy of GBM. However, there are currently no TMZ-sensitizing drugs available in the clinic. Here we aimed to study whether the antidiabetic drug Sitagliptin can inhibit the survival, stemness and autophagy of GBM cells, and thus enhance TMZ cytotoxicity. We used CCK-8, EdU, colony formation, TUNEL and flow cytometry assays to assess cell proliferation and apoptosis; sphere formation and limiting dilution assays to measure self-renewal and stemness of glioma stem cells (GSCs); Western blot, qRT-PCR or immunohistochemical analysis to measure the expression of proliferation or stem cell markers; Western blot/fluorescent analysis of LC3 and other molecules to evaluate autophagy formation and degradation in glioma cells. We found that Sitagliptin inhibited proliferation and induced apoptosis in GBM cells and suppressed self-renewal and stemness of GSCs. The in vitro findings were further confirmed in glioma intracranial xenograft models. Sitagliptin administration prolonged the survival time of tumor-bearing mice. Sitagliptin could inhibit TMZ-induced protective autophagy and enhance the cytotoxicity of TMZ in glioma cells. In addition, Sitagliptin acted as a dipeptidyl peptidase 4 inhibitor in glioma as well as in diabetes, but it did not affect the blood glucose level and body weight of mice. These findings suggest that Sitagliptin with established pharmacologic and safety profiles could be repurposed as an antiglioma drug to overcome TMZ resistance, providing a new option for GBM therapy.

Sulforaphane alleviates lung ischemia‑reperfusion injury through activating Nrf‑2/HO‑1 signaling

Oxidative stress and inflammation are both involved in the pathogenesis of lung ischemia-reperfusion (I/R) injury. Sulforaphane (SFN) is a natural product with cytoprotective, anti-inflammatory, and antioxidant properties. The present study hypothesized that SFN may protect against lung I/R injury via the regulation of antioxidant and anti-inflammatory-related pathways. A rat model of lung I/R injury was established, and rats were randomly divided into 3 groups: Sham group, I/R group, and SFN group. It was shown that SFN protected against a pathological inflammatory response via inhibition of neutrophil accumulation and in the reduction of the serum levels of the pro-inflammatory cytokines, IL-6, IL-1β, and TNF-α. SFN treatment also significantly inhibited lung reactive oxygen species production, decreased the levels of 8-OH-dG and malondialdehyde, and reversed the decrease in the antioxidant activities of the enzymes catalase, superoxide dismutase, and glutathione peroxidase in the lungs of the I/R treated rats. In addition, SFN ameliorated I/R-induced lung apoptosis in rats by suppressing Bax and cleaved caspase-3 levels and increased Bcl-2 expression. Furthermore, SFN treatment activated an Nrf2-related antioxidant pathway, as indicated by the increased nuclear transfer of Nrf2 and the downstream HO-1 and NADPH quinone oxidoreductase-1. In conclusion, these findings suggested that SFN protected against I/R-induced lung lesions in rats via activation of the Nrf2/HO-1 pathway and the accompanied anti-inflammatory and anti-apoptotic effects.

Matrine-induced nephrotoxicity via GSK-3β/nrf2-mediated mitochondria-dependent apoptosis

INTRODUCTION

Matrine (MT), an ingredient extracted from the Chinese herb Sophora flavescens, can result in nephrotoxicity because of long-term exposure. However, the underlying mechanism by which MT leads to kidney injury remains unclear. This study aimed to investigate the roles of oxidative stress and mitochondria in MT-induced kidney toxicity both in vitro and in vivo.

METHODS

Mice were exposed to MT for 20 days, and NRK-52E cells were exposed to MT with or without LiCl (a GSK-3β inhibitor), tert-Butylhydroquinone (t-BHQ, an Nrf2 activator), or small interfering RNA.

RESULTS

The results showed that MT caused nephrotoxicity accompanied by an increase in reactive oxygen species (ROS) accumulation and mitochondrial dysfunction. Meanwhile, MT significantly upregulated glycogen synthase kinase-3β (GSK-3β) activity, released cytochrome c (Cyt C) and cleaved caspase-3, decreased the activity of nuclear factor-erythroid 2-related Factor 2 (Nrf2), and reduced the expression of heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), which led to the inactivation of antioxidant enzymes and the activation of apoptosis. In addition, GSK-3β inhibition by LiCl or small interfering RNA pretreatment or Nrf2 activation by t-BHQ pretreatment attenuated the toxic effects of MT in NRK-52E cells.

CONCLUSIONS

Taken together, these results revealed that MT-induced apoptosis triggered kidney toxicity and that GSK-3β or Nrf2 might serve as a promising nephroprotective target for MT-induced kidney injury.

Bioactive Constituents of Verbena officinalis Alleviate Inflammation and Enhance Killing Efficiency of Natural Killer Cells

Natural killer (NK) cells play key roles in eliminating pathogen-infected cells. Verbena officinalis (V. officinalis) has been used as a medical plant in traditional and modern medicine for its anti-tumor and anti-inflammatory activities, but its effects on immune responses remain largely elusive. This study aimed to investigate the potential of V. officinalis extract (VO extract) to regulate inflammation and NK cell functions. We examined the effects of VO extract on lung injury in a mouse model of influenza virus infection. We also investigated the impact of five bioactive components of VO extract on NK killing functions using primary human NK cells. Our results showed that oral administration of VO extract reduced lung injury, promoted the maturation and activation of NK cells in the lung, and decreased the levels of inflammatory cytokines (IL-6, TNF-α and IL-1β) in the serum. Among five bioactive components of VO extract, Verbenalin significantly enhanced NK killing efficiency in vitro, as determined by real-time killing assays based on plate-reader or high-content live-cell imaging in 3D using primary human NK cells. Further investigation showed that treatment of Verbenalin accelerated the killing process by reducing the contact time of NK cells with their target cells without affecting NK cell proliferation, expression of cytotoxic proteins, or lytic granule degranulation. Together, our findings suggest that VO extract has a satisfactory anti-inflammatory effect against viral infection in vivo, and regulates the activation, maturation, and killing functions of NK cells. Verbenalin from V. officinalis enhances NK killing efficiency, suggesting its potential as a promising therapeutic to fight viral infection.

Abamectin causes cardiac dysfunction in carp via inhibiting redox equilibrium and resulting in immune inflammatory response and programmed cell death

This study aims to investigate the effects of environmentally relevant concentrations of abamectin on the cardiac function of carp and the potential mechanisms. Here, male carp were exposed to abamectin, and cardiac function-related enzymatic markers were examined. Cardiac histopathology, redox equilibrium, inflammation, and cell death were evaluated. Abamectin exposure caused cardiac dysfunction by upregulating lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK), creatine Kinase MB isoenzyme (CK-MB) and white blood cells (WBCs), and decreasing red blood cells (RBCs) and hemoglobin (Hb). DHE staining and biochemical assays revealed that abamectin caused ROS release and oxidative stress by inhibiting Nrf2-ARE pathway. Histopathological and real-time fluorescence quantitative PCR (RT-qPCR) assays revealed that abamectin caused myocardial fiber swelling and inflammatory cell infiltration, enhanced pro-inflammatory cytokines tumor necrosis factor-α (Tnf-α), interleukin-1 beta (Il-1β), and Il-6 levels and attenuated anti-inflammatory cytokines Il-10 and transforming growth factor beta 1 (Tgf-β1) through activating NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa-B (NF-κB) pathway. Tunel staining showed that abamectin triggered cardiac apoptosis via activating p53-mediated mitochondrial apoptosis with elevated bcl2-associated X (Bax), reduced B-cell lymphoma-2 (Bcl-2), and activated Caspase-9 and Caspase-3. Immunoblot analysis revealed that abamectin activated autophagic flow by inhibiting mammalian target of rapamycin (mTOR), resulting in the conversion of LC3B from LC3-I to LC3-II, elevation of autophagy protein 5 (Atg5), and reduction of p62. Overall, abamectin caused cardiac dysfunction in carp via inhibiting redox equilibrium and resulting in immune inflammatory response and programmed cell death.

Hydroxytyrosol mitigates Mycoplasma gallisepticum-induced pulmonary injury through downregulation of the NF-κB/NLRP3/IL-1β signaling pathway in chicken

In this study, the anti-inflammatory and antiapoptotic effects of hydroxytyrosol (HT) in Mycoplasma gallisepticum (MG)-infected chicken were investigated, and the underlying molecular mechanisms were explored. The results revealed severe ultrastructural pathological changes after MG infection in the lung tissue of chicken, including inflammatory cell infiltration, thickening of the lung chamber wall, visible cell swelling, mitochondrial cristae rupture, and ribosome shedding. MG possibly activated the nuclear factor κB (NF-κB)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)/interleukin (IL)-1β signaling pathway in the lung. However, HT treatment significantly ameliorated MG-induced pathological damage of the lung. HT reduced the magnitude of pulmonary injury after MG infection by reducing apoptosis and releasing the proinflammatory factors. Compared with the MG-infected group, the HT-treated group exhibited significant inhibition of the expression of NF-κB/NLRP3/IL-1β signaling-pathway-related genes; for example, the expressions of NF-κB, NLRP3, caspase-1, IL-1β, IL-2, IL-6, IL-18, and TNF-α significantly decreased (P < 0.01 or <0.05). In conclusion, HT effectively inhibited MG-induced inflammatory response and apoptosis and protected the lung by blocking the activation of NF-κB/NLRP3/IL-1β signaling pathway and reducing the damage caused by MG infection in chicken. This study revealed that HT may be a suitable and effective anti-inflammatory drug against MG infection in chicken.

Celastrol targeting Nedd4 reduces Nrf2-mediated oxidative stress in astrocytes after ischemic stroke

Stroke is the second leading cause of death worldwide, and oxidative stress plays a crucial role. Celastrol exhibits strong antioxidant properties in several diseases; however, whether it can affect oxidation in cerebral ischemic-reperfusion injury (CIRI) remains unclear. This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms. Here, we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2 (Nrf2). Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry, we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4 (Nedd4) and then released Nrf2 from Nedd4 in astrocytes. Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI, which was significantly blocked by celastrol. Furthermore, by inhibiting oxidative stress and astrocyte activation, celastrol effectively rescued neurons from axon damage and apoptosis. Our study uncovered Nedd4 as a direct target of celastrol, and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.

Association between autophagy and acute pancreatitis

Autophagy pathway involves maintaining intracellular homeostasis by regulating the degradation of cytoplasmic components. Disfunction of autophagic process has been confirmed to be critical mechanism in many diseases, including cancer, inflammation, infection, degeneration and metabolic disorders. Recent studies have shown that autophagy is one of the early events in acute pancreatitis. Impaired autophagy promotes the abnormal activation of zymogen granules and results in apoptosis and necrosis of exocrine pancreas. Furthermore, multiple signal paths involve progression of acute pancreatitis by regulating autophagy pathway. This article provides a comprehensive review of the recent advances in epigenetic regulation of autophagy and the role of autophagy in acute pancreatitis.

Characteristics of New Oxygen-Carrying Plasma and Its Application Prospects in the Treatment of Severe Acute Pancreatitis

ABSTRACT

Oxygen-carrying plasma, a new type of colloid substitute, is composed of hydroxyethyl starch and acellular hemoglobin-based oxygen carriers. It can supplement colloidal osmotic pressure and rapidly improve the body's oxygen supply. The resuscitation effect of the new oxygen-carrying plasma in animal shock models is better than that of hydroxyethyl starch or hemoglobin-based oxygen carriers alone. It can reduce the histopathological damage and mortality associated with severe acute pancreatitis, and it is expected to become an interesting treatment method for severe acute pancreatitis. This article reviews the characteristics of the new oxygen-carrying plasma, its role in fluid resuscitation, and its application prospects in the treatment of severe acute pancreatitis.

Integration of scRNA-Seq and Bulk RNA-Seq Reveals Molecular Characterization of the Immune Microenvironment in Acute Pancreatitis

Acute pancreatitis (AP) is an acute inflammatory disease of the exocrine pancreas. The pathogenesis of AP is still unclear, and there is currently no specific treatment. A variety of immune cells infiltrate in AP, which may play an important role in the progression of the disease. In this study, for the first time, scRNA-Seq and Bulk RNA-Seq data were used to show the characteristics of immune cell infiltration in AP, and to explore the specific molecular markers of different cell types. The present study also investigated cell-to-cell communication networks using the CellChat package, and AP-specific gene signatures (Clic1, Sat1, Serpina3n, Atf3, Lcn2, Osmr, Ccl9, Hspb1, Anxa2, Krt8, Cd44, Cd9, Hsp90aa1, Tmsb10, Hmox1, Fxyd5, Plin2, Pnp) were identified through integrative analysis of multiple sequencing datasets. We also defined disease-specific associated genes in different cell types, revealing dynamic changes through cell trajectory and pseudo-time analysis using the Monocle2 package. The results showed that macrophages were significantly increased in acute pancreatitis, and the number of interactions and interaction weight/strength of the macrophages in AP were significantly higher than those in the controls. The activities of various signaling pathways were abnormally regulated such as apoptosis, oxidative stress, lysosome, autophagy, ferroptosis, and inflammatory responses signaling pathways. In conclusion, this study comprehensively depicted the immune microenvironment of AP, explored the interaction network between different cell types, and defined AP-specific gene signatures, providing many new directions for basic research in AP.

Elsholtzia bodinieri Vaniot Ameliorated Acute Lung Injury by NQO1, BCL2 and PTGS2 In Silico and In Vitro Analyses

Acute lung injury (ALI) is a clinical respiratory disease caused by various factors, which lacks effective pharmacotherapy to reduce the mortality rate. Elsholtzia bodinieri Vaniot is an annual herbaceous plant used as a traditional herbal tea and folk medicine. Here we used bioinformatic databases and software to explore and analyze the potential key genes in ALI regulated by E. bodinieri Vaniot, including B cell leukemia/lymphoma 2 (Bcl2), prostaglandin-endoperoxide synthase 2 (Ptgs2) and NAD(P)H dehydrogenase, quinone 1 (Nqo1). In an inflammatory cells model, we verified bioinformatics results, and further mechanistic analysis showed that methanol extract of E. bodinieri Vaniot (EBE) could alleviate oxidative stress by upregulating the expression of NQO1, suppress pyroptosis by upregulating the expression of BCL2, and attenuate inflammation by downregulating the expression of PTGS2. In sum, our results demonstrated that EBE treatment could alleviate oxidative stress, suppress pyroptosis and attenuate inflammation by regulating NQO1, BCL2 and PTGS2 in a cells model, and E. bodinieri Vaniot might be a promising source for functional food or as a therapeutic agent.

Geniposidic acid protects lipopolysaccharide-induced acute lung injury via the TLR4/MyD88 signaling pathway in vitro and in vivo

BACKGROUND

Acute lung injury (ALI) is a common respiratory disease and is a serious threat to human health due to the lack of effective treatment. Geniposidic acid (GPA) is an iridoid glucoside extracted from Gardeniae jasminoides Ellis and can treat inflammation-related diseases. This study aimed to investigate the regulatory functions of GPA on lipopolysaccharide (LPS)-induced ALI and its potential mechanism, providing effective strategies for the clinical treatment of ALI.

METHODS

ALI models were constructed by LPS in Sprague-Dawley rats and pulmonary epithelial cells. The function of GPA was investigated by hematoxylin-eosin staining, lung function assessment, Western blot, Masson staining, and Sirius Red staining, quantitative real-time PCR, enzyme-linked immunosorbent assay, cell counting kit-8 assay, apoptosis analysis, and immunofluorescence assays.

RESULTS

Functionally, GPA increased survival, relieved pulmonary epithelial function in response to LPS, repressed pulmonary fibrosis and inflammation caused by ALI in vivo; GPA also repressed pulmonary epithelial cell injury and inflammation induced by LPS in vitro. Mechanistically, GPA decreased the protein levels of TLR4 and MyD88 and accelerated the nuclear export of p65, suggesting that GPA repressed the activation of p65.

CONCLUSION

GPA protected LPS-induced ALI through the TLR4/MyD88 signaling pathway.

Hair follicle-MSC-derived small extracellular vesicles as a novel remedy for acute pancreatitis

BACKGROUND

Hair follicle-derived mesenchymal stem cell (HF-MSC)-based therapies protect against acute pancreatitis (AP). However, accumulating evidence suggests that MSC-based therapy mainly involves the secretion of MSC-derived small extracellular vesicles (MSC-sEVs) through paracrine effects. Thus, the present research investigated the therapeutic effect of HF-MSC-sEVs in AP and the underlying mechanisms.

METHODS

SEVs were purified from cultured HF-MSC supernatant. The effects of sEVs in vitro were analyzed on caerulein-simulated pancreatic acinar cells (PACs). The therapeutic potential of sEVs in vivo was examined in a caerulein-induced AP model. The organ distribution of sEVs in mice was determined by near-infrared fluorescence (NIRF) imaging. Serum specimens and pancreatic tissues were collected to analyze the inhibition of inflammation and pyroptosis in vivo, as well as the appropriate infusion route: intraperitoneal (i.p.) or intravenous (i.v.) injection.

RESULTS

HF-MSC-sEVs were taken up by PACs and improved cell viability in vitro. In vivo, sEVs were abundant in the pancreas, and the indicators of pancreatitis, including amylase, lipase, the inflammatory response, myeloperoxidase (MPO) expression and histopathology scores, in sEV-treated mice were markedly improved compared with those in the AP group, especially via tail vein injection. Furthermore, we revealed that sEVs observably downregulated the levels of crucial pyroptosis proteins in both PACs and AP tissue.

CONCLUSIONS

We innovatively demonstrated that HF-MSC-sEVs could alleviate inflammation and pyroptosis in PACs in AP, suggesting a refreshing cell-free remedy for AP.

Pulmonary Fibrosis as a Result of Acute Lung Inflammation: Molecular Mechanisms, Relevant In Vivo Models, Prognostic and Therapeutic Approaches

Pulmonary fibrosis is a chronic progressive lung disease that steadily leads to lung architecture disruption and respiratory failure. The development of pulmonary fibrosis is mostly the result of previous acute lung inflammation, caused by a wide variety of etiological factors, not resolved over time and causing the deposition of fibrotic tissue in the lungs. Despite a long history of study and good coverage of the problem in the scientific literature, the effective therapeutic approaches for pulmonary fibrosis treatment are currently lacking. Thus, the study of the molecular mechanisms underlying the transition from acute lung inflammation to pulmonary fibrosis, and the search for new molecular markers and promising therapeutic targets to prevent pulmonary fibrosis development, remain highly relevant tasks. This review focuses on the etiology, pathogenesis, morphological characteristics and outcomes of acute lung inflammation as a precursor of pulmonary fibrosis; the pathomorphological changes in the lungs during fibrosis development; the known molecular mechanisms and key players of the signaling pathways mediating acute lung inflammation and pulmonary fibrosis, as well as the characteristics of the most common in vivo models of these processes. Moreover, the prognostic markers of acute lung injury severity and pulmonary fibrosis development as well as approved and potential therapeutic approaches suppressing the transition from acute lung inflammation to fibrosis are discussed.

Nrf2 Pathway and Autophagy Crosstalk: New Insights into Therapeutic Strategies for Ischemic Cerebral Vascular Diseases

Cerebrovascular disease is highly prevalent and has a complex etiology and variable pathophysiological activities. It thus poses a serious threat to human life and health. Currently, pathophysiological research on cerebrovascular diseases is gradually improving, and oxidative stress and autophagy have been identified as important pathophysiological activities that are gradually attracting increasing attention. Many studies have found some effects of oxidative stress and autophagy on cerebrovascular diseases, and studies on the crosstalk between the two in cerebrovascular diseases have made modest progress. However, further, more detailed studies are needed to determine the specific mechanisms. This review discusses nuclear factor erythroid 2-related factor 2 (Nrf2) molecules, which are closely associated with oxidative stress and autophagy, and the crosstalk between them, with the aim of providing clues for studying the two important pathophysiological changes and their crosstalk in cerebrovascular diseases as well as exploring new target treatments.

The combination of high glucose and LPS induces autophagy in bovine kidney epithelial cells via the Notch3/mTOR signaling pathway

BACKGROUND

Aside respiratory diseases, beef cattle may also suffer from serious kidney diseases after transportation. Hyperglycemia and gram-negative bacterial infection may be the main reasons why bovine is prone to severe kidney disease during transportation stress, however, the precise mechanism is still unclear. The purpose of the current study is to explore whether the combined treatment of high glucose (HG) and lipopolysaccharide (LPS) could induce madin-darby bovine kidney (MDBK) cells injury and autophagy, as well as investigate the potential molecular mechanisms involved.

RESULTS

As we discovered, the combined effect of HG and LPS decreased MDBK cells viability. And, HG and LPS combination also induced autophagy in MDBK cells, which was characterized by increasing the expression of LC3-II/I and Beclin1 and decreasing p62 expression. LC3 fluorescence signal formation was also significantly increased by HG and LPS combination treatment. Furthermore, we measured whether the mammalian target of rapamycin (mTOR) and the Notch3 signaling pathways were involved in HG and LPS-induced autophagy. The results showed that the combination of HG and LPS significantly increased the protein expression of Notch3 and decreased protein expression of p-mTOR, indicating that Notch3 and mTOR signaling pathways were activated. However, co-treatment with the Notch3 inhibitor (DAPT) could reverse the induction of autophagy, and increased the protein expression of p-mTOR.

CONCLUSIONS

This study demonstrated that the combination effect of HG and LPS could induce autophagy in MDBK cells, and the Notch3/mTOR signaling pathway was involved in HG and LPS-induced autophagy.

Glycyl-L-histidyl-L-lysine-Cu2+ attenuates cigarette smoke-induced pulmonary emphysema and inflammation by reducing oxidative stress pathway

Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder manifested as chronic airway inflammation and persistent airflow limitation with the essential mechanism as inflammatory response and oxidative stress induced by toxic exposures such as cigarette smoke (CS). Glycyl-L-histidyl-L-lysine (GHK) is a nontoxic tripeptide involved in the process of healing and regeneration as a natural product. With the combination of Cu(II), glycyl-L-histidyl-L-lysine-Cu²⁺ (GHK-Cu) improves antioxidative and anti-inflammatory bioavailability, and they might offer potential therapeutic properties for COPD. Thus, the present study aimed to identify the potential effects of GHK-Cu on emphysema induced by cigarette smoke.

Methods: In the in vivo experiment, C57BL/6J mice were exposed to CS for 12 weeks to induce pulmonary emphysema. GHK-Cu was injected intraperitoneally at doses of 0.2, 2 and 20 μg/g/day in 100 µl of saline on alternative days from the 1st day after CS exposure. The effects of GHK-Cu on the morphology of CS-induced emphysema, the inflammatory response and oxidative stress were evaluated. The antioxidative effect of GHK-Cu on human alveolar epithelial A549 cells was assessed in vitro.

Results: GHK-Cu treatment attenuated the CS-induced emphysematous changes and partially reversed the matrix metalloprotein -9 (MMP-9)/tissue inhibitor of metalloproteinases-1 (TIMP-1) imbalance in the lung tissue. GHK-Cu reduced the inflammation and oxidation by decreasing the expression of inflammatory cytokines (IL-1β and TNF-α) in the bronchoalveolar lavage and the enzymatic activity of MPO and MDA in the lung homogenate while restoring the T-AOC and GSH content. Furthermore, administration of GHK-Cu reversed the increase in NF-κB expression induced by CS and increased the Nrf2 level, as an antioxidant defense component, in mice with chronic CS exposure. In CSE-exposed human alveolar epithelial A549 cells, GHK-Cu also inhibited oxidative stress by suppressing MDA levels and restoring T-AOC and GSH levels, which were modulated by upregulating Nrf2 expression.

Conclusion: GHK-Cu treatment attenuated CS-induced emphysema by anti-inflammation by downregulating NF-κB and antioxidation via upregulation of the Nrf2/Keap1 in lung tissues.

Clostridium butyricum Protects Against Pancreatic and Intestinal Injury After Severe Acute Pancreatitis via Downregulation of MMP9

Background: Evidence have shown that gut microbiota plays an important role in the development of severe acute pancreatitis (SAP). In addition, matrix metalloproteinase-9 (MMP9) plays an important role in intestinal injury in SAP. Thus, we aimed to determine whether gut microbiota could regulate the intestinal injury during SAP via modulating MMP9.

Methods: In this study, the fecal samples of patients with SAP (n = 72) and healthy controls (n = 32) were analyzed by 16S rRNA gene sequencing. In addition, to investigate the association between gut microbiota and MMP9 in intestinal injury during SAP, we established MMP9 stable knockdown Caco2 and HT29 cells in vitro and generated a MMP9 knockout (MMP9−/−) mouse model of SAP in vivo.

Results: We found that the abundance of Clostridium butyricum (C. butyricum) was significantly decreased in the SAP group. In addition, overexpression of MMP9 notably downregulated the expressions of tight junction proteins and upregulated the expressions of p-p38 and p-ERK in Caco2 and HT29 cells (p &lt; 0.05). However, C. butyricum or butyrate treatment remarkably upregulated the expressions of tight junction proteins and downregulated the expressions of MMP9, p-p38 and p-ERK in MMP9-overexpressed Caco2 and HT29 cells (p &lt; 0.05). Importantly, C. butyricum or butyrate could not affect the expressions of tight junction proteins, and MMP9, p-p38 and p-ERK proteins in MMP9-knockdown cells compared with MMP9-knockdown group. Consistently, C. butyricum or butyrate could not attenuate pancreatic and intestinal injury during SAP in MMP9−/− mice compared with the SAP group.

Conclusion: Collectively, C. butyricum could protect against pancreatic and intestinal injury after SAP via downregulation of MMP9 in vitro and in vivo.

The gut-lung axis in severe acute Pancreatitis-associated lung injury: The protection by the gut microbiota through short-chain fatty acids

The role of gut microbiota in regulating the intestinal homeostasis, as well as the pathogenesis of severe acute pancreatitis-associated lung injury (PALI) is widely recognized. The bioactive functions of metabolites with small molecule weight and the detail molecular mechanisms of PALI mediated by "gut-lung axis" have gradually raised the attentions of researchers. Several studies have proved that short-chain fatty acids (SCFAs) produced by gut microbiome play crucial roles and varied activities in the process of PALI. However, relevant reviews reporting SCFAs in the involvement of PALI is lacking. In this review, we firstly introduced the synthetic and metabolic pathways of SCFAs, as well as the transport and signal transduction routes in brief. Afterwards, we focused on the possible mechanisms and clues of SCFAs to participate in the fight against PALI which referred to the inhibition of pathogen proliferation, anti-inflammatory effects, enhancement of intestinal barrier functions, and the maintenance and regulation of immune homeostasis via pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). In addition, the latest reported pathological and physiological mechanisms of the gut-lung axis involved in PALI were reviewed. Finally, we summarized the potential therapeutic interventions of PALI by targeting SCFAs, including dietary fiber supplementation, direct supplementation of SCFAs/prebiotics/probiotics, and drugs administration, which is expected to provide new sights for clinical use in the future.

Follistatin-like 1 ameliorates severe acute pancreatitis associated lung injury via inhibiting the activation of NLRP3 inflammasome and NF-κB pathway

OBJECTIVE

Severe acute pancreatitis (SAP) is one of the most common abdominal conditions of digestive system that usually causes acute lung injury through systemic inflammation. Follistatin-like 1 (FSTL-1) has been reported to have anti-inflammatory and anti-apoptotic effects in a variety of diseases. The aim of this study was to investigate the effects of FSTL-1 on SAP-associated lung injury (SAPALI) and the underlying mechanism.

METHODS

SAP model was induced by intraperitoneal injection of the L-arginine in C57BL/6 mice. The haematoxylin and eosin (H&E) staining was applied to determine the severity of lung and pancreatic injury. ELISA kits were used to determine serum amylase and inflammatory cytokines levels. TUNEL staining was carried out to measure cell apoptosis. Western blotting was applied to analyze the related proteins of NLRP3 inflammasome and NF-κB pathways.

RESULTS

FSTL-1 was significantly increased in the lung of SAP mice. Knockout of FSTL-1 ameliorated pancreatic injury, lung injury, inflammation and apoptosis in mice with SAP. Moreover, the protein levels of NLRP3, ASC, Caspase-1, p-p65 and p-IκBα were obviously reduced in the FSTL-1 KO+SAP group in comparison with SAP group, suggesting that inhibition of FSTL-1 repressed the activation of the NLRP3 inflammasome and NF-κB pathway.

CONCLUSION

This study helps us understand the mechanism of FSTL-1 in SAPALI and might provide a potential new strategy for the treatment of SAPALI.

Intestinal Microbiota - An Unmissable Bridge to Severe Acute Pancreatitis-Associated Acute Lung Injury

Severe acute pancreatitis (SAP), one of the most serious abdominal emergencies in general surgery, is characterized by acute and rapid onset as well as high mortality, which often leads to multiple organ failure (MOF). Acute lung injury (ALI), the earliest accompanied organ dysfunction, is the most common cause of death in patients following the SAP onset. The exact pathogenesis of ALI during SAP, however, remains unclear. In recent years, advances in the microbiota-gut-lung axis have led to a better understanding of SAP-associated lung injury (PALI). In addition, the bidirectional communications between intestinal microbes and the lung are becoming more apparent. This paper aims to review the mechanisms of an imbalanced intestinal microbiota contributing to the development of PALI, which is mediated by the disruption of physical, chemical, and immune barriers in the intestine, promotes bacterial translocation, and results in the activation of abnormal immune responses in severe pancreatitis. The pathogen-associated molecular patterns (PAMPs) mediated immunol mechanisms in the occurrence of PALI via binding with pattern recognition receptors (PRRs) through the microbiota-gut-lung axis are focused in this study. Moreover, the potential therapeutic strategies for alleviating PALI by regulating the composition or the function of the intestinal microbiota are discussed in this review. The aim of this study is to provide new ideas and therapeutic tools for PALI patients.

The anti-inflammatory feature of glucagon-like peptide-1 and its based diabetes drugs—Therapeutic potential exploration in lung injury

Since 2005, GLP-1 receptor (GLP-1R) agonists (GLP-1RAs) have been developed as therapeutic agents for type 2 diabetes (T2D). GLP-1R is not only expressed in pancreatic islets but also other organs, especially the lung. However, controversy on extra-pancreatic GLP-1R expression still needs to be further resolved, utilizing different tools including the use of more reliable GLP-1R antibodies in immune-staining and co-immune-staining. Extra-pancreatic expression of GLP-1R has triggered extensive investigations on extra-pancreatic functions of GLP-1RAs, aiming to repurpose them into therapeutic agents for other disorders. Extensive studies have demonstrated promising anti-inflammatory features of GLP-1RAs. Whether those features are directly mediated by GLP-1R expressed in immune cells also remains controversial. Following a brief review on GLP-1 as an incretin hormone and the development of GLP-1RAs as therapeutic agents for T2D, we have summarized our current understanding of the anti-inflammatory features of GLP-1RAs and commented on the controversy on extra-pancreatic GLP-1R expression. The main part of this review is a literature discussion on GLP-1RA utilization in animal models with chronic airway diseases and acute lung injuries, including studies on the combined use of mesenchymal stem cell (MSC) based therapy. This is followed by a brief summary.

Lack of STAT6 enhances murine acute lung injury through NLRP3/p38 MAPK signaling pathway in macrophages

Background

Signal transducer and activator of transcription 6 (STAT6) is an intracelluar transcriotion factor and NLRP3 (Nod-like receptor containing a pyrin domain 3) is a component of NLRP3 inflammasome in pyroptotic cells. There was increased activation of STAT6 and expression of NLRP3 in mice with murine acute lung injury (ALI). However, it is unknown their roles in the development of murine ALI. We in this study, investigated the effects of STAT6 signaling on murine ALI and pyroptosis in STAT6 knock-out (KO) mice and macrophages.

Results

STAT6 was activated in the lung tissues of mice 2 days after intratracheal treatmemt with 5 mg/kg LPS. Lack of STAT6 expression in KO mice induced more severe lung inflammation, associated with elevated neutrophil influx and expression of TNF-alpha, IL-6 and IL-1beta in the inflamed lung tissues. In addition, the expression of NLRP3, ASC (apoptosis-associated speck-like protein containing a CARD), p-p38 MAPK (p38 mitogen-activated protein kinase) and ratio of LC3-II/I (microtubule-associated protein-1 light chain-3) was increased, accompanied with the increased polarization of Siglec-F(−) subtype macrophages in KO mice with ALI. Further studies in bone marrow-derived macrophages (BMDMs) revealed that lack of STAT6 increased the expression of NLRP3 and p-p38 MAPK, in association with elevated expression of TNF-alpha, IL-1beta and Calreticulin in LPS-treated KO BMDMs.

Conclusions

Lack of STAT6 exacerbated murine ALI through improving the expression of NLRP3 and activation of p38 MAPK in macrophages. STAT6 has an immune suppressive role in the development of ALI and would be a promising therapeutic target in the treatment of ALI and possibly among patients with acute respiratory distress syndrome (ARDS).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-022-00500-9.

Sitagliptin Alleviates Radiation-Induced Intestinal Injury by Activating NRF2-Antioxidant Axis, Mitigating NLRP3 Inf--lammasome Activation, and Reversing Gut Microbiota Disorder

Radiation-induced intestinal injury is a common and critical complication of radiotherapy for pelvic or abdominal tumors, with limited therapeutic strategies and effectiveness. Sitagliptin, a dipeptidyl peptidase IV (DPP4) inhibitor, has previously been reported to alleviate total body irradiation- (TBI-) induced damage of hematopoietic system in mice, but its effect on radiation-induced intestinal injury remains unclear. In this study, we confirmed that Sitagliptin could not only protect mice from death and weight loss caused by whole abdominal irradiation (WAI) but also improve the morphological structure of intestine and the regeneration ability of enterocytes. In addition, Sitagliptin significantly inhibited the production of radiation-induced proinflammatory cytokines and reduced the number of apoptotic intestinal epithelial cells and γ-H2AX expression. In vitro, we demonstrated that Sitagliptin protected HIEC-6 cells from ionizing radiation, resulting in increased cell viability and reduced DNA damage. Mechanistically, the radiation protection of Sitagliptin might be related to the upregulation of NRF2 level and the decrease of NLRP3 inflammasome activity. Importantly, Sitagliptin significantly restored radiation-induced changes in bacterial composition. In conclusion, our results suggested that Sitagliptin could reduce WAI-induced intestinal injury in mice, which may provide novel therapeutic strategy for radiation-induced intestinal injury.

Role of Dipeptidyl Peptidase 4 Inhibitors in Antidiabetic Treatment

In recent years, important changes have occurred in the field of diabetes treatment. The focus of the treatment of diabetic patients has shifted from the control of blood glucose itself to the overall management of risk factors, while adjusting blood glucose goals according to individualization. In addition, regulators need to approve new antidiabetic drugs which have been tested for cardiovascular safety. Thus, the newest class of drugs has been shown to reduce major adverse cardiovascular events, including sodium-glucose transporter 2 (SGLT2) and some glucagon like peptide 1 receptor (GLP1) analog. As such, they have a prominent place in the hyperglycemia treatment algorithms. In recent years, the role of DPP4 inhibitors (DPP4i) has been modified. DPP4i have a favorable safety profile and anti-inflammatory profile, do not cause hypoglycemia or weight gain, and do not require dose escalation. In addition, it can also be applied to some types of chronic kidney disease patients and elderly patients with diabetes. Overall, DPP4i, as a class of safe oral hypoglycemic agents, have a role in the management of diabetic patients, and there is extensive experience in their use.

[Abdominal puncture drainage alleviates severe acute pancreatitis in rats by activating Nrf-2/HO-1 pathway and promoting autophagy]

OBJECTIVE

To assess the effect of early abdominal puncture drainage (APD) on autophagy and Nrf-2/HO-1 pathway in rats with severe acute pancreatitis (SAP) and explore the possibile mechanism.

METHODS

Thirty-two male SD rats were randomly divided into sham-operated (SO) group, SAP group with retrograde injection of 4% sodium taurocholate, APD group with insertion of a drainage tube into the lower right abdomen after SAP induction, and APD + ZnPP group with intraperitoneal injection of 30 mg/kg ZnPP 12 h before APD modeling. Blood samples were collected from the rats 12 h after modeling for analysis of amylase and lipase levels and serum inflammatory factors. The pathological changes of the pancreatic tissue were observed with HE staining. Oxidative stress in the pancreatic tissue was detected with colorimetry, and sub-organelle structure and autophagy in pancreatic acinar cells were observed by transmission electron microscopy. The expressions of autophagy-related proteins and Nrf-2/HO-1 pathway were detected using RT-PCR and Western blotting.

RESULTS

Compared with those in SAP group, the rats with APD treatment showed significantly alleviated pathologies in the pancreas, reduced serum levels of lipase, amylase and inflammatory factors, lowered levels of oxidative stress, and activated expressions of Nrf-2/HO-1 pathway in the pancreas. The ameliorating effect of ADP was significantly inhibited by ZnPP treatment before modeling. APD obviously reversed mitochondrial and endoplasmic reticulum damages and p62 accumulation induced by SAP.

CONCLUSION

APD treatment can suppress oxidative stress and repair impaired autophagy in rats with SAP by activating the Nrf-2/HO-1 pathway, thereby reducing the severity of SAP.