Among patients with necrotizing pancreatitis, the effects of organ failure on mortality are more critical than those of infection. Bacteremia, age, American Society of Anesthesiologists class, persistent organ failure in the first week, and pancreatic necrosis were identified as the predictors of mortality.
Hypoxia/reoxygenation (H/R)-induced injury is the key factor associated with islet graft dysfunction. This study aims to examine the effect of mesenchymal stem cells (MSCs) on islet survival and insulin secretion under H/R conditions. Islets from rats were isolated, purified, cultured with or without MSCs, and exposed to hypoxia (O(2) ≤ 1%) for 8 h and reoxygenation for 24 and 48 h, respectively. Islet function was evaluated by measuring basal and glucose-stimulated insulin secretion (GSIS). Apoptotic islet cells were quantified using Annexin V-FITC. Anti-apoptotic effects were confirmed by mRNA expression analysis of hypoxia-resistant molecules, HIF-1α, HO-1, and COX-2, using semi-quantitative retrieval polymerase chain reaction (RT-PCR). Insulin expression in the implanted islets was detected by immunohistological analysis. The main results show that the stimulation index (SI) of GSIS was maintained at higher levels in islets co-cultured with MSCs. The MSCs protected the islets from H/R-induced injury by decreasing the apoptotic cell ratio and increasing HIF-1α, HO-1, and COX-2 mRNA expression. Seven days after islet transplantation, insulin expression in the MSC-islets group significantly differed from that of the islets-alone group. We proposed that MSCs could promote anti-apoptotic gene expression by enhancing their resistance to H/R-induced apoptosis and dysfunction. This study provides an experimental basis for therapeutic strategies based on enhancing islet function.
The platelet-derived growth factor (PDGF) signaling pathway has been found to play important roles in the development and progression of human cancers by regulating the processes of cell proliferation, apoptosis, migration, invasion, metastasis, and the acquisition of the epithelial-mesenchymal transition (EMT) phenotype. Moreover, PDGF signaling has also been found to alter the expression profile of miRNAs, leading to the reversal of EMT phenotype. Although the role of miRNAs in cancer has been documented, there are very few studies documenting the cellular consequences of targeted re-expression of specific miRNAs. Therefore, we investigated whether the treatment of human pancreatic cancer cells with PDGF could alter the expression profile of miRNAs, and we also assessed the cellular consequences. Our study demonstrates that miR-221 is essential for the PDGF-mediated EMT phenotype, migration, and growth of pancreatic cancer cells. Down-regulation of TRPS1 by miR-221 is critical for PDGF-mediated acquisition of the EMT phenotype. Additionally, the PDGF-dependent increase in cell proliferation appears to be mediated by inhibition of a specific target of miR-221 and down-regulation of p27Kip1.
In 2010, World Health Organization (WHO) reclassified pancreatic neuroendocrine tumors (p-NETs) into 4 main groups: neuroendocrine tumor G1 (NET G1), neuroendocrine tumor G2 (NET G2), neuroendocrine carcinoma G3 (NEC G3), mixed adeno and neuroendocrine carcinoma (MANEC). Clinical value of these newly updated WHO grading criteria has not been rigorously validated. The authors aimed to evaluate the clinical consistency of the new 2010 grading classifications by WHO and the 2010 tumor-node metastasis staging systems by American Joint Committee on Cancer (AJCC) on survivals for patients with surgically resected p-NETs. Moreover, the authors would validate the prognostic value of both criteria for p-NETs.The authors retrospectively collected the clinicopathologic data of 120 eligible patients who were all surgically treated and histopathologically diagnosed as p-NETs from January 2004 to February 2014 in our single institution.The new WHO criteria were assigned to 4 stratified groups with a respective distribution of 62, 35, 17, and 6 patients. Patients with NET G1 or NET G2 obtained a statistically better survival compared with those with NEC G3 or MANEC (P < 0.001). Survivals of NET G1 was also better than those of NET G2 (P = 0.023), whereas difference of survivals between NEC G3 and MANEC present no obvious significance (P = 0.071). The AJCC 2010 staging systems were respectively defined in 61, 36, 12, and 11 patients for each stage. Differences of survivals of stage I with stage III and IV were significant (P < 0.001), as well as those of stage II with III and IV (P < 0.001); whereas comparisons of stage I with stage II and stage III with IV were not statistically significant (P = 0.129, P = 0.286; respectively). Together with radical resection, these 2 systems were both significant in univariate and multivariate analysis (P < 0.05).The newly updated WHO 2010 grading classifications and the AJCC 2010 staging systems could consistently reflect the clinical outcome of patients with surgically resected p-NETs. Meanwhile, both criteria could be independent predictors for survival analysis of p-NETs.
Both classifications accurately reflect the clinical outcome of p-NETs. Surgical margin, the World Health Organization 2010 grading, and the TNM staging systems may all be meaningful prognostic factors impacting the long-term survival of patients with p-NETs.
Summary
Exendin‐4 can stimulate β‐cell replication in mice. Whether it can stimulate β‐cell replication in human islet grafts remains unknown. Therefore, we compared the effects of exendin‐4 on β‐cell replication in mouse and human islet grafts. Islets, isolated from mouse and human donors at different ages, were transplanted into diabetic mice and/or diabetic nude mice that were given bromodeoxyuridine (BrdU) with or without exendin‐4. At 4 weeks post‐transplantation, islet grafts were removed for insulin and BrdU staining and quantification of insulin+/BrdU+ cells. Although diabetes was reversed in all mice transplanting syngeneic mouse islets from young or old donors, normoglycemia was achieved significantly faster in exendin‐4 treated mice. Mouse islet grafts in exendin‐4 treated mice had significantly more insulin+/BrdU+β cells than in untreated mice (P < 0.01). Human islet grafts from ≤22‐year‐old donors had more insulin+/BrdU+β cells in exendin‐4 treated mice than that in untreated mice (P < 0.01). However, human islet grafts from ≥35‐year‐old donors contained few insulin+/BrdU+β cells in exendin‐4 treated or untreated mice. Our data demonstrated that the capacity for β‐cell replication in mouse and human islet grafts is different with and without exendin‐4 treatment and indicated that GLP‐1 agonists can stimulate β‐cell replication in human islets from young donors.
Our results demonstrated that CFA treatment ameliorates autoimmunity in diabetic NOD mice by up-regulating CD4=CD25+Foxp3+ regulatory T cells and increasing TGF-beta1 production. Exendin-4 enhanced the effect of CFA on reversing diabetes in NOD mice by stimulating beta-cell replication.
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