Activation of α7 nicotinic acetylcholine receptors inhibits hepatic necroptosis and ameliorates acute liver injury in mice.

BACKGROUND: Acute liver injury (ALI) is a disease characterized by severe liver dysfunction, caused by significant infiltration of immune cells and extensive cell death with a high mortality. Previous studies demonstrated that the α7 nicotinic acetylcholine receptor (α7nAChR) played a crucial role in various liver diseases. The hypothesis of this study was that activating α7nAChR could alleviate ALI and investigate its possible mechanisms. METHODS: ALI was induced by intraperitoneal injection of lipopolysaccharide (LPS)/D-galactosamine (D-Gal) in wild type (WT), α7nAChR knockout (α7nAChR -/-) and Sting mutation (Stinggt/gt) mice in the presence or absence of a pharmacological selective α7nAChR agonist (PNU-282987). The effects of α7nAChR on hepatic injury, inflammatory response, mitochondrial damage, necroptosis and infiltration of immune cells during ALI were assessed. RESULTS: The expression of α7nAChR in liver tissue was increased in LPS/D-Gal induced ALI mice. Compared to the age-matched WT mice, α7nAChR deficiency decreased the survival rate, exacerbated the hepatic injury accompanied with enhanced inflammatory response and oxidative stress, and aggravated hepatic mitochondrial damage and necroptosis. Conversely, pharmacological activation of α7nAChR by PNU-282987 displayed the opposite trends. Furthermore, PNU-282987 significantly reduced the proportion of infiltrating monocyte-derived macrophages (CD45+CD11bhiF4/80int), M1 macrophages (CD45+CD11b+F4/80+CD86 hiCD163low), Ly6Chi monocytes (CD45+CD11b+MHCⅡ lowLy6C hi), but increased the resident Kupffer cells (CD45+CD11bintF4/80 hiTIM4 hi) in the damaged hepatic tissues caused by LPS/D-Gal. Interestingly, α7nAChR deficiency promoted the STING signaling pathway under LPS/D-Gal stimulation, while PNU-282987 treatment significantly prevented its activation. Finally, it was found that Sting mutation abolished the protective effects against hepatic injury by activating α7nAChR. CONCLUSIONS: Our study revealed that activating α7nAChR could protect against LPS/D-Gal induced ALI by inhibiting hepatic inflammation and necroptosis possibly via regulating immune cells infiltration and inhibiting STING signaling pathway.

Nickel-Molybdenum-Based Three-Dimensional Nanoarrays for Oxygen Evolution Reaction in Water Splitting.

Water splitting is an important approach to hydrogen production. But the efficiency of the process is always controlled by the oxygen evolution reaction process. In this study, a three-dimensional nickel-molybdenum binary nanoarray microstructure electrocatalyst is successfully synthesized. It is grown uniformly on Ni foam using a hydrothermal method. Attributed to their unique nanostructure and controllable nature, the Ni-Mo-based nanoarray samples show superior reactivity and durability in oxygen evolution reactions. The series of Ni-Mo-based electrocatalysts presents a competitive overpotential of 296 mV at 10 mA·cm-2 for an OER in 1.0 M KOH, corresponding with a low Tafel slope of 121 mV dec-1. The three-dimensional nanostructure has a large double-layer capacitance and plenty of channels for ion transfer, which demonstrates more active sites and improved charge transmission. This study provides a valuable reference for the development of non-precious catalysts for water splitting.

Targeting EFHD2 inhibits interferon-γ signaling and ameliorates non-alcoholic steatohepatitis.

BACKGROUND & AIMS: The precise pathomechanisms underlying the development of non-alcoholic steatohepatitis (NASH, also known as metabolic dysfunction-associated steatohepatitis [MASH]) remain incompletely understood. In this study, we investigated the potential role of EF-hand domain family member D2 (EFHD2), a novel molecule specific to immune cells, in the pathogenesis of NASH. METHODS: Hepatic EFHD2 expression was characterized in patients with NASH and two diet-induced NASH mouse models. Single-cell RNA sequencing (scRNA-seq) and double-immunohistochemistry were employed to explore EFHD2 expression patterns in NASH livers. The effects of global and myeloid-specific EFHD2 deletion on NASH and NASH-related hepatocellular carcinoma were assessed. Molecular mechanisms underlying EFHD2 function were investigated, while chemical and genetic investigations were performed to assess its potential as a therapeutic target. RESULTS: EFHD2 expression was significantly elevated in hepatic macrophages/monocytes in both patients with NASH and mice. Deletion of EFHD2, either globally or specifically in myeloid cells, improved hepatic steatosis, reduced immune cell infiltration, inhibited lipid peroxidation-induced ferroptosis, and attenuated fibrosis in NASH. Additionally, it hindered the development of NASH-related hepatocellular carcinoma. Specifically, deletion of myeloid EFHD2 prevented the replacement of TIM4+ resident Kupffer cells by infiltrated monocytes and reversed the decreases in patrolling monocytes and CD4+/CD8+ T cell ratio in NASH. Mechanistically, our investigation revealed that EFHD2 in myeloid cells interacts with cytosolic YWHAZ (14-3-3ζ), facilitating the translocation of IFNγR2 (interferon-γ receptor-2) onto the plasma membrane. This interaction mediates interferon-γ signaling, which triggers immune and inflammatory responses in macrophages during NASH. Finally, a novel stapled α-helical peptide targeting EFHD2 was shown to be effective in protecting against NASH pathology in mice. CONCLUSION: Our study reveals a pivotal immunomodulatory and inflammatory role of EFHD2 in NASH, underscoring EFHD2 as a promising druggable target for NASH treatment. IMPACT AND IMPLICATIONS: Non-alcoholic steatohepatitis (NASH) represents an advanced stage of non-alcoholic fatty liver disease (NAFLD); however, not all patients with NAFLD progress to NASH. A key challenge is identifying the factors that trigger inflammation, which propels the transition from simple fatty liver to NASH. Our research pinpointed EFHD2 as a pivotal driver of NASH, orchestrating the over-activation of interferon-γ signaling within the liver during NASH progression. A stapled peptide designed to target EFHD2 exhibited therapeutic promise in NASH mice. These findings support the potential of EFHD2 as a therapeutic target in NASH.

Laparoscopic common bile duct exploration with primary closure is preferred for selected elderly individuals with choledocholithiasis.

Background: Laparoscopic common bile duct exploration with primary closure (LCBDE-PC) exhibits more benefits than other surgeries for patients with choledocholithiasis. It remains unclear whether it is feasible for and beneficial to elderly individuals. This study aimed to clarify and stratify elderly patients who would benefit from LCBDE-PC. Methods: A retrospective study of 1240 patients with choledocholithiasis who underwent laparoscopic procedures between 2011 and 2019 was conducted. Patients were divided into the young group (<65 years old, n = 708) and the elderly group (≥65 years old, n = 532). Perioperative outcomes were compared between the two groups. Results: Laparoscopic common bile duct exploration with primary closure was successfully performed in 90.20% of the elderly and 94.20% of the young. No significant differences were observed between the two groups regarding reoperation, postoperative bile leakage, residual stones, drainage removal, and postoperative mortality. Compared with the young, the elderly had longer postoperative hospital stay (p = 0.035) and delayed postoperative eating time (p = 0.036) in the matched cohort. Independent risk factors for failed LCBDE-PC were preoperative pancreatitis (p = 0.018), year of the surgeon's experience (p = 0.008), preoperative C-reactive protein level (p = 0.034), preoperative total bilirubin (p = 0.021), impacted common bile duct (CBD) stones (p = 0.006), blood loss (p = 0.001), and edema of the CBD (p = 0.001). A novel nomogram for predicting failed LCBDE-PC in elderly individuals exhibited a sufficient discriminative ability according to the estimated area under the curve (AUC) of 0.869 (95% CI: 0.817-0.921, p < 0.01). Conclusion: Laparoscopic common bile duct exploration with primary closure is safe, feasible, and effective for elderly individuals with choledocholithiasis. Elderly patients with a high risk of failed LCBDE-PC should be cautious of undergoing LCBDE-PC.

Self-Assembly of Selenium-Doped Carbon Quantum Dots as Antioxidants for Hepatic Ischemia-Reperfusion Injury Management.

Hepatic ischemia-reperfusion injury (HIRI) is a critical complication after liver surgery that negatively affects surgical outcomes of patients with the end-stage liver-related disease. Reactive oxygen species (ROS) are responsible for the development of ischemia-reperfusion injury and eventually lead to hepatic dysfunction. Selenium-doped carbon quantum dots (Se-CQDs) with an excellent redox-responsive property can effectively scavenge ROS and protect cells from oxidation. However, the accumulation of Se-CQDs in the liver is extremely low. To address this concern, the fabrication of Se-CQDs-lecithin nanoparticles (Se-LEC NPs) is developed through self-assembly mainly driven by the noncovalent interactions. Lecithin acting as the self-assembly building block also makes a pivotal contribution to the therapeutic performance of Se-LEC NPs due to its capability to react with ROS. The fabricated Se-LEC NPs largely accumulate in the liver, effectively scavenge ROS and inhibit the release of inflammatory cytokines, thus exerting beneficial therapeutic efficacy on HIRI. This work may open a new avenue for the design of self-assembled Se-CQDs NPs for the treatment of HIRI and other ROS-related diseases.

Targeting a novel inducible GPX4 alternative isoform to alleviate ferroptosis and treat metabolic-associated fatty liver disease.

Metabolic-associated fatty liver disease (MAFLD), which is previously known as non-alcoholic fatty liver disease (NAFLD), represents a major health concern worldwide with limited therapy. Here, we provide evidence that ferroptosis, a novel form of regulated cell death characterized by iron-driven lipid peroxidation, was comprehensively activated in liver tissues from MAFLD patients. The canonical-GPX4 (cGPX4), which is the most important negative controller of ferroptosis, is downregulated at protein but not mRNA level. Interestingly, a non-canonical GPX4 transcript-variant is induced (inducible-GPX4, iGPX4) in MAFLD condition. The high fat-fructose/sucrose diet (HFFD) and methionine/choline-deficient diet (MCD)-induced MAFLD pathologies, including hepatocellular ballooning, steatohepatitis and fibrosis, were attenuated and aggravated, respectively, in cGPX4-and iGPX4-knockin mice. cGPX4 and iGPX4 isoforms also displayed opposing effects on oxidative stress and ferroptosis in hepatocytes. Knockdown of iGPX4 by siRNA alleviated lipid stress, ferroptosis and cell injury. Mechanistically, the triggered iGPX4 interacts with cGPX4 to facilitate the transformation of cGPX4 from enzymatic-active monomer to enzymatic-inactive oligomers upon lipid stress, and thus promotes ferroptosis. Co-immunoprecipitation and nano LC-MS/MS analyses confirmed the interaction between iGPX4 and cGPX4. Our results reveal a detrimental role of non-canonical GPX4 isoform in ferroptosis, and indicate selectively targeting iGPX4 may be a promising therapeutic strategy for MAFLD.

Laparoscopic common bile duct exploration with primary closure is beneficial for patients with previous upper abdominal surgery.

BACKGROUND: Previous upper abdominal surgery (PUAS) is considered a contraindication to laparoscopic surgery. Whether LCBDE-PC is feasible and beneficial for patients with PUAS remains unclear. This study aimed to evaluate the feasibility and benefits of LCBDE-PC for patients with PUAS. METHODS: From June 2011 to September 2019, 1167 patients who underwent laparoscopic procedures for choledocholithiasis were reviewed retrospectively. Perioperative outcomes were compared between patients with and without PUAS in un-matched and matched cohorts. RESULTS: LCBDE-PC was performed successfully in 88.3% of patients with PUAS, and 92.5% of patients without PUAS (P > 0.05). Multivariate analysis showed that PUAS was not a risk factor that affected successful performance of LCBDE-PC. Although a higher rate of conversion to open surgery and longer operative time were observed in patients with PUAS, no significant differences were found between patients with and without PUAS in multivariate and propensity score analysis (P > 0.05). A predictive nomogram for LCBDE-PC failure was developed based on potential predictors from the least absolute shrinkage and selection operator (LASSO) regression model. Successful performance of LCBDE-PC was associated with operative time. A linear regression model for operative time showed impacted stone in the CBD and intraoperative laser use was the most important factor in determining the operative time. CONCLUSION: LCBDE-PC is feasible and beneficial for patients with PUAS. However, patients with PUAS with a high possibility of LCBDE-PC failure from the nomogram and a longer operative time from the linear regression model should be cautious when undergoing LCBDE-PC.

Safety and efficacy of laparoscopic common bile duct exploration for the patients with difficult biliary stones: 8 years of experiences at a single institution and literature review.

BACKGROUND: Laparoscopic common bile duct exploration (LCBDE) has gained wide popularity for the treatment of choledocholithiasis. However, it remains unclear whether LCBDE is a better alternative option for the patients with difficult biliary stones. Thus, the aim of the present study was to explore the safety and efficacy of LCBDE for these patients by retrospectively analyzing our data and combing with literature review. METHODS: Between September 2011 and February 2019, 1064 consecutive patients who underwent LCBDE at Shanghai Tenth People's Hospital were reviewed. The clinical data of patients with difficult biliary stones were selected and retrospectively analyzed. RESULTS: Of these patients, 334 cases were confirmed with difficult biliary stones, and the overall complete stone clearance rate was 98.8% (330/334). 34 cases (10.2%) were performed with laser lithotripsy. A total of 296 patients (88.6%) underwent primary closure of common bile duct, and T-tube drainage was indwelled in 38 patients (11.4%). No bile duct injury, bleeding, perforation and surgery-related deaths were observed. The overall morbidity rate was 6.6%. 16 cases (4.8%) occurred in bile leakage with primary closure procedure, and all of them were managed successfully with conservative therapy. The median follow-up period was 9 months with stone recurrence occurring in 9 patients (2.7%). There was no evidence of bile duct stricture in all cases. CONCLUSIONS: The current study suggests that LCBED is a considerable safe and effective option for the patients with difficult biliary stones. A randomized clinical trial is needed to further evaluate the benefit of LCBDE in this subgroup.

Laparoscopy-guided percutaneous microwave ablation for symptomatic 12.8 cm hepatic hemangioma with low blood loss and short hospital stay post-operation: A case report and literature review.

We described a patient with symptomatic giant hepatic hemangioma (GHH) treated with laparoscopic guided percutaneous microwave ablation (MWA). A 58 years' old woman was referred to our hospital who presented with upper abdominal distension and appetite loss for more than 1 year. The medical history included untreated multiple hepatic hemangiomas (HH) that had been detected 13 years ago and hypertension for more than 12 years. Initial laboratory tests revealed D-dimer mild increase and negative tumor markers. Magnetic resonance (MR) imaging demonstrated multiple nodules of different sizes in the liver and the largest lesion was located on the left lobe (longest diameter 12.8 cm), which replaced the whole enlarged left lobe and compressed the gastric body and inferior vena cava. Contrast-enhanced ultrasound (CEUS) and contrast-enhanced MR imaging both showed the typical enhancement pattern of hemangioma and abnormal perfusion was seen in the surrounding liver parenchyma. With the laparoscopy guidance, we performed microwave ablation till the whole tumor was seen atrophy. The total operation duration was 2 hours, with intra-operative blood loss less than 20 ml. The post-operative course was uneventful. The patient was discharged 3 days after the operation. Abdominal distension decreased, appetite improved, blood pressure controlled at normal level after the operation. MR revealed significant volume reduction of the tumor after the operation.

Long noncoding RNA H19 regulates the therapeutic efficacy of mesenchymal stem cells in rats with severe acute pancreatitis by sponging miR-138-5p and miR-141-3p.

BACKGROUND: Patients with severe acute pancreatitis (SAP), which is characterized by high morbidity and mortality, account for an increasing medical burden worldwide. We previously found that mesenchymal stem cells (MSCs) could attenuate SAP and that expression of long noncoding RNA H19 (LncRNA H19) was upregulated in rats receiving MSCs. In the present study, we investigated the mechanisms of LncRNA H19 regulating the therapeutic efficacy of MSCs in the alleviation of SAP. METHODS: MSCs transfected with LncRNA H19 overexpression and knockdown plasmids were intravenously injected into rats 12 h after sodium taurocholate (NaT) administration to induce SAP. RESULTS: Overexpressing LncRNA H19 in MSCs significantly enhanced the anti-inflammatory capacity of the MSCs, inhibited autophagy via promotion of focal adhesion kinase (FAK)-associated pathways, and facilitated cell proliferation by increasing the level of ß-catenin in rats with SAP. LncRNA H19 functioned as a competing endogenous RNA by sponging miR-138-5p and miR-141-3p. Knocking down miR-138-5p in MSCs increased the expression of protein tyrosine kinase 2 (PTK2, encoding FAK) to suppress autophagy, while downregulating miR-141-3p enhanced the level of ß-catenin to promote cell proliferation. CONCLUSIONS: In conclusion, LncRNA H19 effectively increased the therapeutic efficacy of MSCs in rats with SAP via the miR-138-5p/PTK2/FAK and miR-141-3p/ß-catenin pathways.

Resveratrol improves the therapeutic efficacy of bone marrow-derived mesenchymal stem cells in rats with severe acute pancreatitis.

OBJECTIVE: Bone marrow-derived mesenchymal stem cells (BMSCs) are effective in the treatment of severe acute pancreatitis (SAP), but their therapeutic effects could still be improved. In order to optimize the clinical application of BMSCs, we adopted the strategy of resveratrol (Res) pretreatment of BMSCs (Res-BMSCs) and applied it to a rat model of sodium taurocholate (NaT)-induced acute pancreatitis. METHODS: SAP was induced by injection of 3% NaT into the pancreatic duct and successful induction of SAP occurred after 12 h. Rats were treated with BMSCs, Res or BMSCs primed with Res at 40 mmol/L, Vandetanib (ZD6474) daily oral dosages of 50 mg/kg vandetanib. RESULTS: Res stimulated BMSCs to secrete vascular endothelial growth factor A (VEGFA), activated the downstream phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and inhibited pancreatic cell apoptosis. In addition, conditioned medium (CM) from Res-BMSCs enhanced the proliferation of human umbilical vein endothelial cells (HUVECs) in vitro, increased resistance to apoptosis and promoted the expression of angiogenesis-related proteins CD31, VEGF and VEGFR2 in pancreatic tissue, but Vandetanib partly abolished these effects by blocking the VEGFA- mediated pathway. CONCLUSION: Resveratrol-preprocessed BMSCs can activate the PI3K/AKT signaling pathway in pancreatic cells and HUVECs through paracrine release of VEGFA; thus, achieving the therapeutic effect of resisting apoptosis of pancreatic cells and promoting regeneration of damaged blood vessels. Res pretreatment may be a new strategy to improve the therapeutic effect of BMSCs on SAP.

Bone marrow-derived mesenchymal stem cells alleviate severe acute pancreatitis-induced multiple-organ injury in rats via suppression of autophagy.

Patients with severe acute pancreatitis (SAP) represent a substantial challenge to medical practitioners due to the high associated rates of morbidity and mortality and a lack of satisfactory therapeutic outcomes. In a previous study, our group demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs) can ameliorate SAP; however, the mechanisms of action remain to be fully understood. BMSCs were intravenously injected into SAP rats 12 h after experimental induction of SAP using sodium taurocholate (NaT). Histopathological changes and the levels of pro-inflammatory mediators were assessed by hematoxylin and eosin (H&E) staining and ELISA, respectively. Autophagy levels were assessed using qRT-PCR, western blotting, immunohistochemistry, immunofluorescence, and transmission electron microscopy. AR42J cells and human umbilical vein endothelial cells (HUVECs) were administered BMSC-conditioned media (BMSC-CM) after NaT treatment, and cell viability was measured using a Cell Counting Kit-8 (CCK-8) and flow cytometry. In vivo, BMSCs effectively reduced multiple systematic inflammatory responses, suppressed the activation of autophagy, and improved intestinal dysfunction. In vitro, BMSC-CM significantly improved the viability of injured cells, promoted angiogenesis, and decreased autophagy. We therefore propose that the administration of BMSCs alleviates SAP-induced multiple organ injury by inhibiting autophagy.

Melatonin safeguards against fatty liver by antagonizing TRAFs-mediated ASK1 deubiquitination and stabilization in a ß-arrestin-1 dependent manner.

Melatonin has been previously shown to prevent nonalcoholic fatty liver disease (NAFLD), yet the underlying mechanisms are poorly understood. Here, we identified a previously unknown regulatory action of melatonin on apoptosis signal-regulating kinase 1 (ASK1) signaling pathway in the pathogenesis and development of NAFLD. Although melatonin administration did not alter food intake, it significantly alleviated fatty liver phenotypes, including the body weight gain, insulin resistance, hepatic lipid accumulation, steatohepatitis, and fibrosis in a high-fat diet (HFD)-induced NAFLD mouse model (in vivo). The protection of melatonin against NAFLD was not affected by inactivation of Kupffer cell in this model. In NAFLD mice liver, ASK1 signal cascade was substantially activated, evidence by the enhancement of total ASK1, phospho-ASK1, phospho-MKK3/6, phospho-p38, phospho-MKK4/7, and phospho-JNK. Melatonin treatment significantly suppressed the ASK1 upregulation and the phosphorylation of ASK1, MKK3/6, MKK4/7, p38, and JNK. Mechanistically, we found that lipid stress triggered the interaction between ASK1 and TNF receptor-associated factors (TRAFs), including TRAF1, TRAF2, and TRAF6, which resulted in ASK1 deubiquitination and thereby increased ASK1 protein stability. Melatonin did not alter ASK1 mRNA level; however, it activated a scaffold protein ß-arrestin-1 and enabled it to bind to ASK1, which antagonized the TRAFs-mediated ASK1 deubiquitination, and thus reduced ASK1 protein stability. Consistent with these findings, knockout of ß-arrestin-1 in mice partly abolished the protection of melatonin against NAFLD. Taken together, our results for the first time demonstrate that melatonin safeguards against NAFLD by eliminating ASK1 activation via inhibiting TRAFs-mediated ASK1 deubiquitination and stabilization in a ß-arrestin-1 dependent manner.

Clinical role of frequency-doubled double-pulse neodymium YAG laser lithotripsy for removal of difficult biliary stones in laparoscopic common bile duct exploration.

BACKGROUND: The optimal methods for patients with difficult biliary stones remain under debate. The aim of this study was to evaluate the role of frequency-doubled double-pulse neodymium YAG (FREDDY) laser lithotripsy for removing difficult biliary stones during laparoscopic common bile duct exploration (LCBDE). METHODS: Between March 2013 and January 2015, 42 consecutive patients with difficult biliary stones who underwent LCBDE with FREDDY laser lithotripsy were included in this study. The clinical data of all patients were retrospectively collected and analysed. RESULTS: Bile ducts were completely cleared in all patients. The complications related to laser lithotripsy were not noted. A total of 38 patients (90.5%) underwent primary closure of common bile duct, and T-tube drainage was applied to four patients (9.5%). No bile duct injury, bleeding and perforation were observed. There were no post-operative surgery-related deaths. Bile leakage occurred in four patients (9.5%) with primary closure procedure, and all of them were managed successfully with conservative therapy. The median follow-up period was 42.8 months, with no evidence of bile duct stricture and stone recurrence in all patients. CONCLUSIONS: The LCBDE combined with FREDDY laser lithotripsy appear to be effective and safe for the treatment of difficult biliary stones.

Bone marrow-derived mesenchymal stem cells ameliorate severe acute pancreatitis by inhibiting necroptosis in rats.

The treatment and prognosis for severe acute pancreatitis (SAP) is currently unsatisfactory showing a high incidence of morbidity and mortality. Here, we investigated the effect of bone marrow-derived mesenchymal stem cells (BMSCs) on SAP in rats and explored the possible mechanisms. The common bile duct of each model rat was occluded at the liver hilum, and the induction of SAP was achieved by retrograde perfusion of 3% sodium taurocholate (NaT). Prepared BMSCs were intravenously injected via the tail vein. Pancreatic acinar cells (PACs) were isolated from rat pancreas, and induced by TNF-α. In the present study, we found that necroptosis was activated in NaT-induced acute-necrotized pancreatitis, and transplanted BMSCs could inhibit necroptosis, repair pancreatic injury, and reduce systemic inflammatory response. In addition, necrostatin-1 (Nec-1), as the inhibitor of receptor-interacting protein kinase 1 (RIPK1), could also reduce SAP to some extent. Besides, we detected that BMSCs could also promote regeneration of damaged pancreatic tissues. Furthermore, in vitro, we also investigated that BMSCs could suppress TNF-α-induced necroptosis and improve the viability of PACs. In addition, Nec-1 and knockdown of receptor-interacting protein kinase 3 (RIPK3) or mixed lineage kinase domain-like protein (MLKL) could also inhibit necrosis of PACs induced by TNF-α. BMSCs ameliorated SAP and reduced injury of PACs by suppressing the activation of the necroptosis signaling pathway.

Bone marrow-derived mesenchymal stem cells attenuate severe acute pancreatitis via regulation of microRNA-9 to inhibit necroptosis in rats.

AIMS: Severe acute pancreatitis (SAP) is an acute disease of the digestive system accompanied by pancreatic necrosis. We have found that bone marrow-derived mesenchymal stem cells (BMSCs) can attenuate SAP, but the underlying mechanism remains unclear. The present study was conducted to explore the possible mechanisms by which BMSCs alleviate SAP. MAIN METHODS: BMSCs and BMSCs engineered to overexpress microRNA (miR)-9 (miR-9-BMSCs) were transplanted into rat models of SAP via the tail vein. Pancreatic acinar cells (PACs) were isolated from rat pancreatic tissues and induced by tumor necrosis factor-α (TNF-α) in vitro. KEY FINDINGS: miR-9-BMSCs significantly reduced the systemic inflammatory response, impeded the necroptosis signaling pathway and promoted regeneration of damaged pancreas in vivo. miR-9-BMSCs secreted miR-9, which targeted the gene encoding receptor interacting protein kinase 1 in PACs induced by TNF-α, to inhibit necroptosis and ameliorate SAP. SIGNIFICANCE: miR-9-BMSCs can reduce SAP-induced injury to pancreatic tissues and PACs by regulating miR-9 to suppress necroptosis.

N-Acetylcysteine enhances the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation in rats with severe acute pancreatitis.

BACKGROUND: Severe acute pancreatitis (SAP) is a high mortality disease, for which there is a lack of effective therapies. Previous research has demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs), which have immunomodulatory and antioxidant properties, have potential for the treatment of SAP. It remains unclear, however, whether the free radical scavenger N-acetylcysteine (NAC) can enhance the therapeutic efficacy of BMSC transplantation in SAP. In this study, we investigated the effect of combining treatment with NAC and BMSCs in a rat model of SAP. METHODS: SAP was induced by injection of sodium taurocholate into the pancreatic duct and, after successful induction of SAP, the rats were treated with BMSCs and NAC, either singly or in combination. RESULTS: After 3 days, serum levels of amylase, proinflammatory factors, malondialdehyde, and reactive oxygen species were significantly decreased in animals treated with BMSCs or NAC, compared with vehicle-treated animals. In contrast, total glutathione, superoxide dismutase and catalase were markedly increased after treatment with BMSCs or NAC. However, oxidative stress markers and inflammatory factors were significantly improved in the SAP + BMSCs + NAC group compared with those in the SAP + NAC group and the SAP + BMSCs group. CONCLUSIONS: Combined NAC and BMSC therapy was found to alleviate oxidative stress damage to the pancreas and to inhibit the inflammatory response to a significantly greater extent than single therapy with either BMSCs or NAC. Because NAC enhances the therapeutic efficacy of BMSC transplantation in a rat model of SAP, combined therapy may provide a promising new approach for the treatment of SAP.

Bone marrow-derived mesenchymal stromal cells ameliorate severe acute pancreatitis in rats via hemeoxygenase-1-mediated anti-oxidant and anti-inflammatory effects.

BACKGROUND AND AIMS: It has been previously verified that mesenchymal stromal cells (MSCs) have a good therapeutic effect on severe acute pancreatitis (SAP) and the potential for regeneration of damaged pancreatic tissue, but the exact molecular mechanism remains unclear. In this study, we demonstrated the therapeutic effect of bone morrow MSCs (BMSCs) on SAP, probably by targeting heme oxygenase-1 (HO-1). METHODS: Six hours after SAP induction, either phosphate-buffered saline (PBS) or BMSCs were transfused into the caudal vein of rats, zinc protoporphyrin (ZnPP) was administered intraperitoneally. Pancreatic pathological scoring, serum levels of amylase and inflammatory factors, as well as levels of reactive oxygen species (ROS), malondialdehyde (MDA) and myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) activity in the pancreas were evaluated. RESULTS: Our data showed that BMSCs significantly reduce inflammation and oxidative stress, reduce apoptosis and promote angiogenesis of damaged pancreas. Moreover, BMSCs increased the level of HO-1 in the serum and pancreatic tissue in rats with SAP. In addition, the protective effect of BMSCs was partially neutralized by the HO-1 activity inhibitor ZnPP, suggesting a key role of HO-1 in the therapeutic effect of BMSCs on SAP. CONCLUSIONS: BMSCs ameliorated SAP, probably by inducing expression of HO-1, which can exert anti-inflammatory and anti-oxidant effects, reduce apoptosis and promote angiogenesis.