Chronic pancreatitis in a caerulein-induced mouse model is associated with an altered gut microbiome.

BACKGROUND: Chronic pancreatitis (CP) is an inflammatory disease of the pancreas with loss of exocrine/endocrine functions as well as development of fibrosis. Dysbiosis of gut microbiome has been shown to be involved in the pathogenesis of many disease processes. Therefore, we aim to investigate the alteration in gut microbiome associated with CP in caerulein-induced mouse model. METHODS: CP was induced in C57Bl/6 by using caerulein injections (50 µg/kg/h, i.p., x7, twice weekly for 10 weeks). Stool samples were collected either one week after end of injection (10-week CP) or 6 weeks (16-week CP). DNA was extracted from stool samples and V4 region of 16S rDNA was sequenced for microbiome analysis. RESULTS: CP was strongly associated with the alteration in the composition of the gut microbiome, evidenced by differences in α and ß diversity. When ß diversity was measured using both weighted and unweighted UniFrac distances, stool from control mice is significantly different from mice on 10-week or 16-week CP (q < 0.01). The α-diversity measured by Faith's phylogenetic diversity was lowest in stool from healthy control and highest in stool from mice with 16-week CP (p < 0.001). Bacteria taxa differentially enriched in CP samples were detected using linear discriminant analysis. Bacteria from genera Bifidobacterium, Akkermansia, and Desulfovibrio were enriched in samples from 10-week CP mice. Bacteria from genera Allobaculum, Prevotella, and Bacteroides were enriched in samples from 16-week CP mice. CONCLUSION: Together, these analyses reveal pronounced alteration in the gut microbiome composition, diversity, and function when mice develop CP.

Molecular targeted approaches for treatment of pancreatic cancer.

Human pancreatic cancer remains a highly malignant disease with almost similar incidence and mortality despite extensive research. Many targeted therapies are under development. However, clinical investigation showed that single targeted therapies and most combined therapies were not able to improve the prognosis of this disease, even though some of these therapies had excellent anti-tumor effects in pre-clinical models. Cross-talk between cell proliferation signaling pathways may be an important phenomenon in pancreatic cancer, which may result in cancer cell survival even though some pathways are blocked by targeted therapy. Pancreatic cancer may possess different characteristics and targets in different stages of pathogenesis, maintenance and metastasis. Sensitivity to therapy may also vary for cancer cells at different stages. The unique pancreatic cancer structure with abundant stroma creates a tumor microenvironment with hypoxia and low blood perfusion rate, which prevents drug delivery to cancer cells. In this review, the most commonly investigated targeted therapies in pancreatic cancer treatment are discussed. However, how to combine these targeted therapies and/or combine them with chemotherapy to improve the survival rate of pancreatic cancer is still a challenge. Genomic and proteomic studies using pancreatic cancer samples obtained from either biopsy or surgery are recommended to individualize tumor characters and to perform drug sensitivity study in order to design a tailored therapy with minimal side effects. These studies may help to further investigate tumor pathogenesis, maintenance and metastasis to create cellular expression profiles at different stages. Integration of the information obtained needs to be performed from multiple levels and dimensions in order to develop a successful targeted therapy.

Myricetin induces pancreatic cancer cell death via the induction of apoptosis and inhibition of the phosphatidylinositol 3-kinase (PI3K) signaling pathway.

Pancreatic cancer is the fourth leading cause of cancer related deaths and is a disease with poor prognosis. It is refractory to standard chemotherapeutic drugs or to novel treatment modalities, making it imperative to find new treatments. In this study, using both primary and metastatic pancreatic cancer cell lines, we have demonstrated that the flavonoid myricetin induced pancreatic cancer cell death in vitro via apoptosis, and caused a decrease in PI3 kinase activity. In vivo, treatment of orthotopic pancreatic tumors with myricetin resulted in tumor regression and decreased metastatic spread. Importantly, myricetin was non-toxic, both in vitro and in vivo, underscoring its use as a therapeutic agent against pancreatic cancer.

The role of heat shock proteins in gastrointestinal diseases.

Heat shock proteins (HSPs) are a highly conserved family of proteins which inhabit almost all subcellular locations and cellular membranes. Depending on their location, these proteins perform a variety of chaperoning functions including folding of newly synthesised polypeptides. HSPs also play a major role in the protection of cells against stressful and injury-inciting stimuli. By virtue of this protective function, HSPs have been shown to prevent acinar cell injury in acute pancreatitis. Also, the levels of HSPs have been shown to be markedly elevated in various forms of cancers when compared with non-transformed cells. Further, inhibition of HSPs has been shown to induce apoptotic cell death in cancer cells suggesting that inhibition of HSPs has a potential to emerge as novel anti-cancer therapy, either as monotherapy or in combination with other chemotherapeutic agents. Several studies have suggested that HSPs can interact with and inhibit both intrinsic and extrinsic pathways of apoptosis at multiple sites. Besides the anti-apoptotic role of HSPs, recent studies suggest that they play a role in the generation of anti-cancer immunity, and attempts have been made to utilise this property of HSPs in the generation of anti-cancer vaccines. The anti-apoptotic function and mechanism of various subtypes of HSPs as well as the current status of anti-HSP therapy are discussed in this review.

Impact of toll-like receptor 4 on the severity of acute pancreatitis and pancreatitis-associated lung injury in mice.

BACKGROUND AND AIMS: Acute pancreatitis is an inflammatory disease involving acinar cell injury, and the rapid production and release of inflammatory cytokines, which play a dominant role in local pancreatic inflammation and systemic complications. Toll-like receptor 4 (TLR4) initiates a complex signalling pathway when it interacts with lipopolysaccharide (LPS), which ultimately results in a proinflammatory response. We hypothesised that TLR4 is important in the pathophysiology of acute pancreatitis, independently of LPS. Using two different models of acute pancreatitis, we investigated how genetic deletion of TLR4 or its co-receptor CD14 effects its progression and severity. METHODS: We induced acute pancreatitis by administering either caerulein or L-arginine to wild-type, TLR4(-/-), and CD14(-/-) mice. Control mice received normal saline injections. The severity of acute pancreatitis was determined by measuring serum amylase activity, quantifying myeloperoxidase (MPO) activity in the pancreatic tissue, and histologically assessing acinar cell injury. RESULTS: It was found that administering caerulein and L-arginine to wild-type mice resulted in acute pancreatitis (as assessed by hyperamylasaemia, oedema, increased pancreatic MPO activity, and pancreatic necrosis) and associated lung injury. The same treatment to TLR4(-/-) or CD14(-/-) mice resulted in significantly less severe acute pancreatitis, and reduced lung injury. We found no evidence of either bacteria or LPS in the blood or in pancreatic tissue. CONCLUSIONS: The severity of acute pancreatitis is ameliorated in mice that lack either TLR4 or CD14 receptors. Furthermore, these results indicate that TLR4 plays a significant pro-inflammatory role independently of LPS in the progression of acute pancreatitis.

Receiver operating characteristics curve analysis of body fat & body mass index in dyslipidaemic Asian Indians.

BACKGROUND & OBJECTIVES: Optimal limit of body mass index (BMI) for Asian Indians remains to be defined. In this study, we describe the anthropometric and lipid profiles and determine the appropriate cut-offs of BMI for defining obesity in dyslipidaemic patients. METHODS: Correlations were carried out between lipid profile and anthropometric variables in 217 dyslipidaemic Asian Indians and the data were compared to those of 123 healthy historical controls. Receiver operating characteristics (ROC) curve analysis was carried out to determine the appropriate cut-offs of BMI for defining obesity taking the percentage of body fat (% BF) as the standard. RESULTS: Dyslipidaemic patients had high waist-hip ratio (W-HR) and percentage of BF. The prevalence of obesity as measured by percentage of BF was significantly (P < 0.05) higher as compared to obesity defined by the BMI cut-off. W-HR was the most important independent predictor (odds ratio: 2.8; 95% CI: 1.02-7.83) of atherogenic dyslipidaemia on multivariate logistic regression analysis. On ROC curve analysis the suggested appropriate cut-offs of BMI were; males 24.0 kg/m2 (sensitivity, 74.7%, and specificity, 79.7%), and females 23.0 kg/m2 (sensitivity, 85.7% and specificity, 62.5%). According to the suggested lower limits of BMI, an additional 15 per cent dyslipidaemic patients will be diagnosed as obese. INTERPRETATION & CONCLUSION: The observations in dyslipidaemic Asian Indians suggest high prevalence rates of generalized and abdominal obesity, and that high values of W-HR alone predisposes to atherogenic dyslipidaemia. Further, obesity may be optimally defined by a lower cut-off of BMI. The revised criteria for the BMI-based diagnosis of obesity will lead to a more rational management of dyslipidaemia in Asian Indians.

Anthropometry and body composition in northern Asian Indian patients with type 2 diabetes: receiver operating characteristics (ROC) curve analysis of body mass index with percentage body fat as standard.

AIMS: To determine the anthropometric profile and appropriate cut off of body mass index (BMI) to define obesity in Asian Indians with Type 2 diabetes mellitus (T2DM). METHODS: Three hundred and eighty T2DM patients (213 males and 167 females) in northern India were subjected to anthropometric and body fat analysis (derived from skinfold thickness). The latter was considered as "standard" for defining obesity. Receiver Operating Characteristics (ROC) curves were drawn for males and females to determine the appropriate limits of BMI to define obesity. RESULTS: Mean values of percentage of body fat (%BF) were 40.2 +/- 6.2% and 29.4 +/- 7.1% in females and males, respectively. Of particular note, substantial percentage of patients had high values of waist-hip ratio (W-HR) [males > 0.95 (53.9%), and females > 0.80 (88.6%)] indicating significant abdominal obesity, and high % BF [males > 25 % BF (73.2%), females > 30% BF (92.2%)] indicating generalized obesity as well. Significantly higher prevalence of obesity was observed in both males (p < 0.001) and females (p < 0.001) when estimated by %BF (males > 25%, females > 30%), as compared to BMI (> 25 kg/m2 in both males and females). ROC curve analysis showed that with %BF taken as the 'standard' for determining obesity, sensitivity and specificity of BMI of > 25 kg/m2 were low. For BMI > 22 kg/m2 in males and > 23 kg/m2 in females, sensitivity increased and there was decrease in overall misclassification. CONCLUSIONS: The data of current study suggest strikingly high prevalence of abdominal obesity, and generalized obesity as determined by %BF in T2DM patients, and that cut offs for defining obesity by BMI are lower than the suggested limit of 25 kg/m2. Revised definition of obesity using lower cut off of BMI, or based on %BF in northern Asian Indian T2DM patients will lead to a more rational application of dietary restriction, lifestyle measures, and use of metformin.

BMI does not accurately predict overweight in Asian Indians in northern India.

Asian Indians are at high risk for the development of atherosclerosis and related complications, possibly initiated by higher body fat (BF). The present study attempted to establish appropriate cut-off levels of the BMI for defining overweight, considering percentage BF in healthy Asian Indians in northern India as the standard. A total of 123 healthy volunteers (eighty-six males aged 18--75 years and thirty-seven females aged 20--69 years) participated in the study. Clinical examination and anthropometric measurements were performed, and percentage BF was calculated. BMI for males was 21.4 (sd 3.7) kg/m(2) and for females was 23.3 (sd 5.5) kg/m(2). Percentage BF was 21.3 (sd 7.6) in males and 35.4 (sd 5.0) in females. A comparison of BF data among Caucasians, Blacks, Polynesians and Asian ethnic groups (e.g. immigrant Chinese) revealed conspicuous differences. Receiver operating characteristic (ROC) curve analysis showed a low sensitivity and negative predictive value of the conventional cut-off value of the BMI (25 kg/m(2)) in identifying subjects with overweight as compared to the cut-off value based on percentage BF (males >25, females >30). This observation is particularly obvious in females, resulting in substantial misclassification. Based on the ROC curve, a lower cut-off value of the BMI (21.5 kg/m(2) for males and 19.0 kg/m(2) for females) displayed the optimal sensitivity and specificity, and less misclassification in identification of subjects with high percentage BF. Furthermore, a novel obesity variable, BF:BMI, was tested and should prove useful for interethnic comparison of body composition. In the northern Indian population, the conventional cut-off level of the BMI underestimates overweight and obesity when percentage BF is used as the standard to define overweight. These preliminary findings, if confirmed in a larger number of subjects and with the use of instruments having a higher accuracy of BF assessment, would be crucial for planning and the prevention and treatment of various obesity-related metabolic diseases in the Asian Indian population.