Yingying Lu

Mucosal adherent bacterial dysbiosis in patients with colorectal adenomas

Recent reports have suggested that the gut microbiota is involved in the progression of colorectal cancer (CRC). The composition of gut microbiota in CRC precursors has not been adequately described. To characterize the structure of adherent microbiota in this disease, we conducted pyrosequencing-based analysis of 16S rRNA genes to determine the bacterial profile of normal colons (healthy controls) and colorectal adenomas (CRC precursors). Adenoma mucosal biopsy samples and adjacent normal colonic mucosa from 31 patients with adenomas and 20 healthy volunteers were profiled using the Illumina MiSeq platform. Principal coordinate analysis (PCoA) showed structural segregation between colorectal adenomatous tissue and control tissue. Alpha diversity estimations revealed higher microbiota diversity in samples from patients with adenomas. Taxonomic analysis illustrated that abundance of eight phyla (Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Chloroflexi, Cyanobacteria, Candidate-division TM7, and Tenericutes) was significantly different. In addition, Lactococcus and Pseudomonas were enriched in preneoplastic tissue, whereas Enterococcus, Bacillus, and Solibacillus were reduced. However, both PCoA and cluster tree analyses showed similar microbiota structure between adenomatous and adjacent non-adenoma tissues. These present findings provide preliminary experimental evidence supporting that colorectal preneoplastic lesion may be the most important factor leading to alterations in bacterial community composition.

The circadian clock gene Bmal1 acts as a potential anti-oncogene in pancreatic cancer by activating the p53 tumor suppressor pathway.

Disruption of the circadian clock has been shown to be associated with tumor development. This study aimed to investigate the role of the core circadian gene Bmal1 in pancreatic cancer (PC). We first found that the levels of Bmal1 were downregulated in PC samples and were closely correlated with the clinicopathological features of patients. To dissect the underlying mechanism, we performed a RNA-seq assay followed by systematic gene function and pathway enrichment analyses. We detected an anti-apoptotic and pro-proliferative transcriptome profile after Bmal1 knockdown in PC cells. Further in vitro and in vivo studies confirmed that Bmal1 overexpression significantly inhibited cell proliferation and invasion and induced G2/M cell cycle arrest, whereas Bmal1 knockdown promoted PC growth, as demonstrated in Bmal1-manipulated AsPC-1 and BxPC-3 cell lines. Our mechanistic studies indicated that Bmal1 could directly bind to the p53 gene promoter and thereby transcriptionally activate the downstream tumor suppressor pathway in a p53-dependent manner. In sum, our findings suggest that Bmal1 acts as an anti-oncogene in PC and represents a potential biomarker for its diagnosis.

miR-183 induces cell proliferation, migration, and invasion by regulating PDCD4 expression in the SW1990 pancreatic cancer cell line

The aim of this study was to investigate the function of miR-183 in the SW1990 cancer cell line, and the mechanisms regulating these processes. miRNAs are known to play important roles in cancer cell development. However, the pattern and biological role of miR-183 in pancreatic cancer remain largely unknown. Here, we have reported the reduction in pancreatic cancer cell growth in vitro by miR-183 intervention, by inducing apoptosis and decreasing the Bcl-2 expression. Moreover, miR-183 was observed to enhance pancreatic cancer cell migration and invasion, whereas inhibition of miR-183 caused an opposite effect. miR-183 inhibition was shown to increase E-cadherin expression and decrease N-cadherin expression. These regulatory actions play an important role in the cancer epithelial-mesenchymal transition (EMT). Mechanistically, we demonstrated that the overexpression of miR-183 decreased the expression of PDCD4 (programmed cell death 4) mRNA and protein, and vice versa. This helped to identify PDCD4 as the target genes in pancreatic cancer. In conclusion, our analyses indicated miR-183 to be an important contributor to cell migration. This could also be used as a potential therapeutic target for pancreatic cancer treatment.

Clinical features and treatment of hypertriglyceridemia‐induced acute pancreatitis during pregnancy: A retrospective study

Aim: To analyze the features and treatment of hypertriglyceridemia‐induced acute pancreatitis (HTGP) during pregnancy. Methods: A retrospective study of 21 pregnant women diagnosed with acute pancreatitis (AP) was performed. Patients were divided into acute biliary pancreatitis (ABP), HTGP, and idiopathic groups according to etiology. Results: 95% of the patients were in the third trimester of gestation. The percentage of patients with HTGP was higher than that of ABP (48% vs.14%). The percentage of severe acute pancreatitis (SAP) in the HTGP group was higher than that in the ABP group (40.0% vs.0%). The Ranson scores for moderately severe acute pancreatitis (MSAP) and SAP in the HTGP group were significantly different (2.50 ± 0.58 vs.3.60 ± 0.89, P < 0.05, respectively). The mean serum triglyceride (TG) levels in the MSAP and SAP HTGP groups were not significantly different (18.81 ± 11.13 vs. 30.53 ± 24.20 mmol/L, P > 0.05, respectively). In the HTGP group, there were five patients given plasma exchange therapy and five not. Plasmapheresis decreased the incidence of systemic inflammatory response syndrome (SIRS) from 100% to 28.6% and the TG level from 20.36 ± 7.41 mmol/L to 5.23 ± 3.62 mmol/L (P < 0.05). The length of hospitalization of the plasmapheresis group was shorter than that of the nonplasmapheresis group (17.3 ± 6.7 days vs. 37.0 ± 20.8 days). Conclusions: Plasma exchange may be safe and effectively administered for HTGP patients during pregnancy with SIRS or multiple organ dysfunction syndrome (MODS). J. Clin. Apheresis 31:571–578, 2016.

Dysbiosis of Intestinal Microbiota and Decreased Antimicrobial Peptide Level in Paneth Cells during Hypertriglyceridemia-Related Acute Necrotizing Pancreatitis in Rats.

Hypertriglyceridemia (HTG) aggravates the course of acute pancreatitis (AP). Intestinal barrier dysfunction is implicated in the pathogenesis of AP during which dysbiosis of intestinal microbiota contributes to the dysfunction in intestinal barrier. However, few studies focus on the changes in intestine during HTG-related acute necrotizing pancreatitis (ANP). Here, we investigated the changes in intestinal microbiota and Paneth cell antimicrobial peptides (AMPs) in HTG-related ANP (HANP) in rats. Rats fed a high-fat diet to induce HTG and ANP was induced by retrograde injection of 3.5% sodium taurocholate into biliopancreatic duct. Rats were sacrificed at 24 and 48 h, respectively. Pancreatic and ileal injuries were evaluated by histological scores. Intestinal barrier function was assessed by plasma diamine oxidase activity and D-lactate level. Systemic and intestinal inflammation was evaluated by tumor necrosis factor alpha (TNFα), interleukin (IL)-1β, and IL-17A expression. 16S rRNA high throughput sequencing was used to investigate changes in intestinal microbiota diversity and structure. AMPs (α-defensin5 and lysozyme) expression was measured by real-time polymerase chain reaction (PCR) and immunofluorescence. The results showed that compared with those of normal-lipid ANP (NANP) groups, the HANP groups had more severe histopathological injuries in pancreas and distal ileum, aggravated intestinal barrier dysfunction and increased TNFα, IL-1β, and IL-17A expression in plasma and distal ileum. Principal component analysis showed structural segregation between the HANP and NANP group. α-Diversity estimators in the HANP group revealed decreased microbiota diversity compared with that in NANP group. Taxonomic analysis showed dysbiosis of intestinal microbiota structure. In the HANP group, at phyla level, Candidatus_Saccharibacteria and Tenericutes decreased significantly, whereas Actinobacteria increased. At genus level, Allobaculum, Bifidobacterium, and Parasutterella increased significantly, while Alloprevotella, Anaerotruncus, Candidatus_Saccharimonas, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, Ruminiclostridium_5, Ruminococcaceae_UCG-005, and Ruminococcaceae_UCG-014 decreased. Compared with those in the NANP rats, mRNA expression of lysozyme and α-defensin5 and protein expression of lysozyme decreased significantly in the HANP rats. Moreover, in the NANP rats and the HANP rats, Allobaculum abundance was inversely correlated with lysozyme expression, while Anaerotruncus abundance was positively correlated with it by Spearman test. In conclusion, intestinal microbiota dysbiosis and decreased AMPs of Paneth cells might participate in the pathogenesis of intestinal barrier dysfunction in HANP.

The inhibitory effects of xanthohumol, a prenylated chalcone derived from hops, on cell growth and tumorigenesis in human pancreatic cancer.

Pancreatic cancer (PC) is one of the most lethal human malignancies worldwide. Here, we demonstrated that xanthohumol (XN), the most abundant prenylated chalcone isolated from hops, inhibited the growth of cultured PC cells and their subcutaneous xenograft tumors. XN treatment was found to induce cell cycle arrest and apoptosis of PC cells (PANC-1, BxPC-3) by inhibiting phosphorylation of signal transducer and activator of transcription 3 (STAT3) and expression of its downstream targeted genes cyclinD1, survivin, and Bcl-xL at the messenger RNA level, which involved in regulation of apoptosis and the cell cycle. Overall, our results suggested that XN presents a promising candidate therapeutic agent against human PC and the STAT3 signaling pathway is its key molecular target.

Dysbiosis of intestinal microbiota and decrease in paneth cell antimicrobial peptide level during acute necrotizing pancreatitis in rats

Objectives Intestinal barrier dysfunction plays an important role in acute necrotizing pancreatitis (ANP) and intestinal microbiota dysbiosis was involved in intestinal barrier failure. Paneth cells protect intestinal barrier and are associated with intestinal microbiota. Here, we investigated changes in intestinal microbiota and antimicrobial peptides of Paneth cells in ileum during ANP. Methods Rats with ANP were established by retrograde injection of 3.5% sodium taurocholate into biliopancreatic duct and sacrificed at 24h and 48h, respectively. Injuries of pancreas and distal ileum were evaluated by histopathological score. Intestinal barrier function was assessed by plasma diamine oxidase activity (DAO) and D-lactate. Systemic and intestinal inflammation was evaluated by TNFα, IL-1β and IL-17A concentration by ELISA, respectively. 16S rRNA high throughput sequencing on fecal samples was used to investigate the changes in intestinal microbiota in the ANP group at 48h. Lysozyme and α-defensin5 were measured by real-time PCR, western blot and immunofluoresence. Results ANP rats had more severe histopathological injuries in pancreas and distal ileum, injured intestinal barrier and increased expression of TNFα, IL-1β and IL-17A in plasma and distal ileum compared with those of the sham-operated (SO) group. Principal component analysis (PCA) showed structural segregation between the SO and ANP groups. Operational taxonomic unit (OTU) number and ACE index revealed decreased microbiota diversity in the ANP group. Taxonomic analysis showed dysbiosis of intestinal microbiota structure. At phyla level, Saccharibacteria and Tenericutes decreased significantly. At genus level, Escherichia-Shigella and Phascolarctobacterium increased significantly, while Candidatus_Saccharimonas, Prevotellaceae_UCG-001, Lachnospiraceae_UCG-001, Ruminiclostridium_5 and Ruminococcaceae_UCG-008 decreased significantly. Lysozyme and α-defensin5 mRNA expression levels decreased significantly in ANP group at 48h. Protein expression of lysozyme decreased in ANP groups at 24h and 48h. Meanwhile, the relative abundance of Escherichia-Shigella correlated inversely with the decrease in lysozyme. Conclusion The disorder in intestinal microbiota and decreases of Paneth cell antimicrobial peptides might participate in the pathogenesis of intestinal barrier dysfunction during ANP.

Palmitic acid aggravates inflammation of pancreatic acinar cells by enhancing unfolded protein response induced CCAAT-enhancer-binding protein β–CCAAT-enhancer-binding protein α activation

Hypertriglyceridemia is an independent risk factor for acute pancreatitis, in which the pathological mechanisms are not fully illustrated. Intracellular inflammatory response is a key pathological response in acute pancreatitis and endoplasmic reticulum stress has been suggested to induce inflammation and CCAAT-enhancer-binding protein expression. Therefore, the current study aims to elucidate the possible relationship between endoplasmic reticulum stress and inflammation in hypertriglyceridemia associated pancreatitis and the possible involvement of CCAAT-enhancer-binding protein. In cholecystokinin-8 stimulated rat primary acinar cells, incubation with palmitic acid caused the activation of endoplasmic reticulum stress and inflammatory responses. Pre-incubation with the chemical chaperone 4-phenylbutyric acid inhibited inflammatory responses induced by palmitic acid, whereas stimulation with the endoplasmic reticulum stress inducer thapsigargin alone induced inflammatory responses. Meanwhile we found that the transcription factors CCAAT-enhancer-binding protein α and CCAAT-enhancer-binding protein β were also induced in the palmitic acid-stimulated pancreatic acinar cells, and were similarly inhibited by 4-phenylbutyric acid pre-incubation and induced by thapsigargin stimulation alone, indicating that endoplasmic reticulum stress was responsible for CCAAT-enhancer-binding protein α and CCAAT-enhancer-binding protein β induction in the pancreatic acinar cells. Knockdown of CCAAT-enhancer-binding protein β by siRNA transfection inhibited inflammatory responses and CCAAT-enhancer-binding protein α induction but did not affect endoplasmic reticulum stress. Our study provides strong evidence that in response to palmitic acid stimulation, endoplasmic reticulum stress induces inflammatory responses in pancreatic acinar cells through induction of the CCAAT-enhancer-binding protein family, wherein CCAAT-enhancer-binding protein β activation is responsible for CCAAT-enhancer-binding protein α activation.

Epidemiology and Etiology of Acute Pancreatitis in Urban and Suburban Areas in Shanghai: A Retrospective Study

Aim To investigate the epidemiology, etiology, and severity of acute pancreatitis (AP) in urban and suburban areas of Shanghai in 2011 and 2016. Methods A retrospective study of patients admitted to Shanghai General Hospital (urban and suburban campuses) with AP in 2011 and 2016 was undertaken. Patients were divided into acute biliary pancreatitis (ABP), hypertriglyceridemic pancreatitis (HTGP), alcoholic pancreatitis, and pancreatitis of other causes according to etiology. Severity of AP was divided into mild AP (MAP), moderately severe AP (MSAP), and severe AP (SAP). Results AP patients in the suburban area increased more rapidly than those in the urban area. The mean onset age of AP in the urban area in 2016 was older than that in the suburban area (p < 0.05). The suburban patients in 2016 have significantly younger mean onset age than those in 2011 (p < 0.05). HTGP incidence in suburban patients increased from 2011 to 2016, which changed little in the urban area. Urban females were more likely to develop HTGP than suburban ones in 2011, which reversed in 2016. As to the male patients, the incidence of HTGP increased in both urban and suburban areas. Nonelderly (<60 years old) patients had higher HTGP incidence than elderly ones in both 2011 and 2016. The descending trend of SAP in the suburban area was more obvious than that in the urban area. The length of hospitalization decreased from 2011 to 2016, especially in SAP patients. Conclusions AP patients increased more rapidly in the suburban area of Shanghai with younger onset age. The incidence of HTGP increased significantly in the suburban area, reminding of the prevention and screening of HTG.