Hongbo Meng

Comparison of different methods for the isolation of mesenchymal stem cells from umbilical cord matrix: Proliferation and multilineage differentiation as compared to mesenchymal stem cells from umbilical cord blood and bone marrow

We have identified the most appropriate method of isolating human umbilical cord matrix‐derived mesenchymal stem cells (UCM‐MSCs) and compared morphological, phenotypic, proliferative and differentiation characteristics of UCM‐MSCs with bone marrow‐derived MSCs (BM‐MSCs) and umbilical cord blood‐derived MSCs (UCB‐MSCs). Three explant culture methods and three enzymatic methods were compared with regards to time for primary culture, cell number, cell morphology, immune phenotype and differentiation potential. Morphological, phenotypic, proliferative and differentiation characteristics of UCM‐MSCs, BM‐MSCs and UCB‐MSCs were also compared. UCM‐MSCs isolated using the 10 mm size tissue explant method led to shorter primary culture time, higher numbers of isolated cells and higher proliferation rates compared with other isolation methods. Immune phenotype and multilineage differentiation capacity did not differ significantly among six groups. UCM‐MSCs had similar characteristics as BM‐MSCs and UCB‐MSCs, including fibroblastic morphology, typical immunophenotypic markers and multilineage differentiation capacity. In comparison with UCB‐MSCs and BM‐MSCs, UCM‐MSCs have higher proliferative capacity, higher rate of chondrogenic differentiation, and higher expression of CD 146. The results suggest that the 10 mm size tissue culture method is the optimal protocol for the isolation of UCM‐MSCs. Given the distinct advantages of UC, such as accessibility, painless acquisition and abundance of cells obtained, we propose that UC be considered an alternative to BM and UCB as a source of MSCs for cell therapy.

The SDF-1/CXCR4 axis regulates migration of transplanted bone marrow mesenchymal stem cells towards the pancreas in rats with acute pancreatitis

Stromal cell-derived factor-1 (SDF-1) and its receptor, CXC chemokine receptor-4 (CXCR4), are important regulators in the migration of bone marrow mesenchymal stem cells (BMSCs). However, the mechanisms underlying this effect in acute pancreatitis (AP) have not been investigated. In this study, BMSCs were identified by specific cell surface markers and differentiation potentials, and labeled with chloromethylbenzamido-1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (CM-Dil) for in vivo cell tracking. AP was induced by retrograde infusion of sodium taurocholate into the common bile duct in rats. The expression of SDF-1 in the injured pancreas was determined by immunohistochemistry and western blot analysis. BMSCs were incubated with or without anti-CXCR4 antibody and the contribution of SDF-1 to the migration of BMSCs was investigated. Our results demonstrated that the expression of SDF-1 was significantly increased in the injured pancreas, and that these levels peaked on days 5–7 and began to decrease on day 10. SDF-1 induced a dose-dependent migration of BMSCs in an in vitro transwell migration assay, which was almost completely blocked by AMD3100 (CXCR4-specific antagonist) or anti-CXCR4 antibody. In addition, by encouraging the migration of CM-Dil-labeled BMSCs, the SDF-1/CXCR4 axis facilitated the repair of the injured pancreas. This effect was inhibited by the anti-CXCR4 antibody. Taken together, these results indicate that the interaction of locally produced SDF-1 with CXCR4 on BMSCs, has an important regulatory role in the migration of BMSCs towards the injured pancreas in AP.

Intravenous hMSCs Ameliorate Acute Pancreatitis in Mice via Secretion of Tumor Necrosis Factor-α Stimulated Gene/Protein 6

The administration of mesenchymal stem cells/multipotent mesenchymal stromal cells (MSCs) to enhance tissue repair is currently undergoing clinical trials. Some studies, including our previous work, have also revealed the beneficial effect of MSCs in severe acute pancreatitis (SAP); however, their mechanisms or mode of action remain controversial. In this study, we demonstrated that intravenously (i.v.)-administered human MSCs (hMSCs) remarkably promoted recovery from experimental SAP without significant engraftment of hMSCs in the damaged pancreas. Interestingly, we found that i.v.-administered hMSCs with knockdown of TSG-6 expression lost most of their anti-inflammatory effects and thus could not significantly ameliorate SAP. As expected, the effects of hMSCs were also duplicated by i.v. infusion of recombinant TSG-6. Furthermore, our results showed that the increase of oxidative stress, activation of the NLRP3 inflammasome and NF-κB signaling in SAP was substantially inhibited following administration of hMSCs or TSG-6, which was dependent on the presence of CD-44 receptors in acinar cells. In conclusion, our study, for the first time, revealed that novel mechanisms are responsible for the immunomodulatory effect of i.v. hMSCs.

Bone Marrow-Derived Mesenchymal Stem Cells Repair Necrotic Pancreatic Tissue and Promote Angiogenesis by Secreting Cellular Growth Factors Involved in the SDF-1 α /CXCR4 Axis in Rats.

Acute pancreatitis (AP), a common acute abdominal disease, 10%–20% of which can evolve into severe acute pancreatitis (SAP), is of significant morbidity and mortality. Bone marrow-derived mesenchymal stem cells (BMSCs) have been reported to have a potential therapeutic role on SAP, but the specific mechanism is unclear. Therefore, we conducted this experiment to shed light on the probable mechanism. We validated that SDF-1α significantly stimulated the expressions of VEGF, ANG-1, HGF, TGF-β, and CXCR4 in BMSCs, which were inhibited by its receptor agonist, AMD3100. The capacities of proliferation, migration, and repair of human umbilical vein endothelial cells were enhanced by BMSCs supernatant. Meanwhile, BMSCs supernatant could also promote angiogenesis, especially after the stimulation with SDF-1α. In vivo, the migration of BMSCs was regulated by SDF-1α/CXCR4 axis. Moreover, transplanted BMSCs could significantly alleviate SAP, reduce the systematic inflammation (TNF-α↓, IL-1β↓, IL-6↓, IL-4↑, IL-10↑, and TGF-β↑), and promote tissue repair and angiogenesis (VEGF↑, ANG-1↑, HGF↑, TGF-β↑, and CD31↑), compared with the SAP and anti-CXCR4 groups. Taken together, the results showed that BMSCs ameliorated SAP and the SDF-1α/CXCR4 axis was involved in the repair and regeneration process.

Braun enteroenterostomy during pancreaticoduodenectomy decreases postoperative delayed gastric emptying

BACKGROUND Modified digestive reconstruction during pancreaticoduodenectomy (PD) may affect the postoperative incidence of delayed gastric emptying (DGE). The purpose of this study is to investigate whether Braun enteroenterostomy following PD can reduce the incidence of DGE. METHODS Four hundred seven patients who received PD with child reconstruction from June 2000 to March 2013 were divided into 2 groups: 206 patients with Braun enteroenterostomy (Child-Braun group) and 201 patients without Braun enteroenterostomy (Child-non-Braun group). Clinical data were retrospectively extracted; univariate and multivariate analyses were performed to investigate the association between Braun enteroenterostomy and DGE. RESULTS DGE was less frequent in the Child-Braun group than in the Child-non-Braun group (6.7% vs. 26.87%, P < .001). The multivariate logistic regression analysis showed that Braun enteroenterostomy was the only significant independent factor associated with the reduced DGE after PD with Child reconstruction, with an odds ratio of 4.485 (95% confidence interval: 2.372 to 8.482, P < .001). CONCLUSION Braun enteroenterostomy reduces the incidence of postoperative DGE associated with PD.

Bone marrow-derived mesenchymal stem cells (BMSCs) repair acute necrotized pancreatitis by secreting microRNA-9 to target the NF-κB1/p50 gene in rats

Acute pancreatitis (AP) is a common acute abdominal disease, 10–20% of which can evolve into severe AP (SAP) causing significant morbidity and mortality. Bone marrow-derived mesenchymal stem cells (BMSCs) have the potential of repairing SAP, but the detailed mechanism remains unknown. We demonstrate here that microRNA-9 (miR-9) modified BMSCs (pri-miR-9-BMSCs) can significantly reduce the pancreatic edema, infiltration, hemorrhage, necrosis, the release of amylase and lipase. Meanwhile, decreased local/systemic inflammatory response (TNF-α↓, IL-1β↓, IL-6↓, HMGB1↓, MPO↓, CD68↓, IL-4↑, IL-10↑, and TGF-β↑) and enhanced regeneration of damaged pancreas (Reg4↑, PTF1↑, and PDX1↑) are also promoted. But these effects diminish or disappear after antagonizing miR-9 (TuD). Besides, we find that miR-9 is negatively correlated with AP and miR-9 agomir which can mimic the effects of pri-miR-9-BMSCs and protect injured pancreas. Furthermore, we investigate that BMSCs deliver miR-9 to the injured pancreas or peripheral blood mononuclear cell (PBMC), which can target the NF-κB1/p50 gene and inhibit the NF-κB signaling pathway (p-P65↓, NF-κB1/p50↓, IκBα↑, IκBβ↑). Taken together, these results show that miR-9 is a key paracrine factor of BMSCs attenuating SAP targeting the NF-κB1/p50 gene and suppressing the NF-κB signaling pathway.

Continuous suture of the pancreatic stump and Braun enteroenterostomy in pancreaticoduodenectomy

AIM To investigate a new modification of pancreaticoduodenectomy (PD)-a mesh-like running suturing of the pancreatic remnant and Brauns enteroenterostomy. METHODS Two hundred and three patients underwent PD from 2009 to 2014 and were classified into two groups: Group A (98 patients), who received PD with a mesh-like running suturing for the pancreatic remnant, and Brauns enteroenterostomy; and Group B (105 patients), who received standard PD. Demographic data, intraoperative findings, postoperative morbidity and perioperative mortality between the two groups were compared by univariate and multivariate analysis. RESULTS Demographic characteristics between Group A and Group B were comparable. There were no significant differences between the two groups concerning perioperative mortality, and operative blood loss, as well as the incidence of the postoperative morbidity, including reoperation, bile leakage, intra-abdominal fluid collection or infection, and postoperative bleeding. Clinically relevant postoperative pancreatic fistula (POPF) and delayed gastric emptying (DGE) were identified more frequently in Group B than in Group A. Technique A (PD with a mesh-like running suturing of the pancreatic remnant and Brauns enteroenterostomy) was independently associated with decreased clinically relevant POPF and DGE, with an odds ratio of 0.266 (95%CI: 0.109-0.654, P = 0.004) for clinically relevant POPF and 0.073 (95%CI: 0.010-0.578, P = 0.013) for clinically relevant DGE. CONCLUSION An additional mesh-like running suturing of the pancreatic remnant and Brauns enteroenterostomy during PD decreases the incidence of postoperative complications and is beneficial for patients.

Risk factors and consequences of conversion to open surgery in laparoscopic common bile duct exploration

BackgroundAlthough laparoscopic common bile duct exploration (LCBDE) has shown many obvious advantages compared with open surgery in the treatment of common bile duct (CBD) stones, it remains unclear regarding risk factors of conversion from LCBDE to open surgery and whether conversion will counteract the advantages of LCBDE. The purpose of this study was to explore risk factors and consequences of conversion from LCBDE to open surgery.MethodsA retrospective study was conducted, using a database of 644 patients with LCBDE between 2011 and 2017. Risk factors for conversion to open surgery were determined based on univariable and multivariable analysis. The consequences of conversion to open surgery in LCBDE were analyzed.ResultsConversion was required in 27 (4.2%) of 644 patients undergoing LCBDE. Independent risk factors for conversion were as follows: the max diameter of stones in CBD (odds ratio (OR) 2.234, 95%CI 1.031–4.842; p = 0.042), edema of CBD (OR 12.530, 95%CI 4.633–33.887; p < 0.001), and multiple stones in CBD (OR 3.438, 95%CI: 1.133–10.428; p = 0.029). These risk factors and their combined were good predictors for conversion in LCBDE. More blood loss, longer operative time, longer postoperative hospital stay, and higher incision infection were identified in patients with conversion than those without conversion. However, no significant differences were observed regarding mortality, readmission within 30 days, reoperation, bile leakage, and intra-abdominal fluid collection.ConclusionConversion to open surgery in LCBDE was associated with acute edematous CBD with large and multiple stones. Conversion can offset the advantages of LCBDE.