Compositional analysis and biological characterization of Cornus officinalis on human 1.1B4 pancreatic ß cells.

Type 1 diabetes (T1D) is an autoimmune disease resulting from the loss of pancreatic ß cells and subsequent insulin production. Novel interventional therapies are urgently needed that can protect existing ß cells from cytokine-induced death and enhance their function before symptomatic onset. Our initial evidence is suggesting that bioactive ingredients within Cornus officinalis (CO) may be able to serve in this function. CO has been extensively used in Traditional Chinese Medicine (TCM) and reported to possess both anti-inflammatory and pro-metabolic effects. We hypothesize that CO treatment may provide a future potential candidate for interventional therapy for early stage T1D prior to significant ß cell loss. Our data demonstrated that CO can inhibit cytokine-mediated ß cell death, increase cell viability and oxidative capacity, and increase expression of NFATC2 (Nuclear Factor of Activated T Cells, Cytoplasmic 2). We have also profiled the bioactive components in CO from multiple sources by HPLC/MS (High Performance Liquid Chromatography/Mass Spectrometry) analysis. Altogether, CO significantly increases the energy metabolism of ß cells while inducing the NFAT pathway to signal for increased proliferation and endocrine function.

Anemarrhena asphodeloides Bunge and its constituent timosaponin-AIII induce cell cycle arrest and apoptosis in pancreatic cancer cells.

Pancreatic cancer is one of the most recalcitrant and lethal of all cancers. We examined the effects of Anemarrhena asphodeloides (AA) and timosaponin-AIII (TAIII), a steroidal saponin present in AA, on pancreatic cancer cell proliferation and aimed to elucidate their potential apoptotic mechanisms of action. Viability assays and cell cycle analysis revealed that both AA and TAIII significantly inhibited pancreatic cancer cell proliferation and cell cycle progression compared to treatment with gemcitabine, the standard chemotherapeutic agent for advanced pancreatic cancer. We identified a dose-dependent increase in caspase-dependent apoptosis and activation of pro-apoptotic PI3K/Akt pathway proteins, with a subsequent downregulation of pro-survival PI3K/Akt pathway proteins, in pancreatic cancer cells treated with AA or TAIII over those treated with gemcitabine.

Circulating PANDER concentration is associated with increased HbA1c and fasting blood glucose in Type 2 diabetic subjects.

AIM: PANcreatic-DERived factor (PANDER, FAM3B) is a novel hormone that regulates glucose levels via interaction with both the endocrine pancreas and liver. Prior studies examining PANDER were primarily conducted in murine models or in vitro but little is known regarding the circulating concentration of PANDER in humans, especially with regard to the association of type 2 diabetes (T2D) or overall glycemic regulation. To address this limitation, we performed a cross-sectional analysis of circulating serum PANDER concentration in association with other hormones that serve as either markers of insulin resistance (insulin and adiponectin) or to metabolic parameters of glycemic control such as fasting HbA1c and blood glucose (FBG). METHODS: Fasting serum was obtained from a commercial biorepository from 300 de-identified adult subjects with 150 T2D and non-T2D adult subjects collected from a population within the United States, respectively, matched on gender, age group and race/ethnicity. Concentration of PANDER, insulin and adiponectin were measured for all samples as determined by commercial ELISA. Metadata was provided for each subject including demography, anthropometry, and cigarette and alcohol use. In addition, fasting blood glucose (FBG) and HbA1c were available on T2D subjects. RESULTS: Multiple linear regression analyses were performed to examine the relationships between circulating log PANDER concentration on HbA1c, fasting glucose, log insulin, log HOMA-ß and log HOMA-IR among T2D subjects and for insulin and adiponectin in non-T2D subjects. A significant linear association was identified between PANDER with fasting HbA1c (ß 0.832 ±â€¯SE 0.22, p = 0.0003) and FBG (ß 20.66 ±â€¯SE 7.43, p = 0.006) within T2D subjects. However, insulin, HOMA-ß, HOMA-IR and adiponectin (p > 0.05) were not found to be linearly associated with PANDER concentration. CONCLUSION: Within T2D subjects, PANDER is modestly linearly associated with increased HbA1c and FBG in a US population. In addition, highest circulating PANDER levels were measured in T2D subjects with HbA1c above 9.9. No association was identified with PANDER and insulin resistance or pancreatic ß-cell function in T2D subjects.

Quantitative proteomic profiling reveals hepatic lipogenesis and liver X receptor activation in the PANDER transgenic model.

PANcreatic-DERived factor (PANDER) is a member of a superfamily of FAM3 proteins modulating glycemic levels by metabolic regulation of the liver and pancreas. The precise PANDER-induced hepatic signaling mechanism is still being elucidated and has been very complex due to the pleiotropic nature of this novel hormone. Our PANDER transgenic (PANTG) mouse displays a selective hepatic insulin resistant (SHIR) phenotype whereby insulin signaling is blunted yet lipogenesis is increased, a phenomena observed in type 2 diabetes. To examine the complex PANDER-induced mechanism of SHIR, we utilized quantitative mass spectrometry-based proteomic analysis using Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) to reveal the global hepatic proteome differences within the PANTG under the metabolic states of fasting, fed and insulin-stimulated conditions. Proteomic analysis identified lipid metabolism as one of the top cellular functions differentially altered in all metabolic states. Differentially expressed proteins within the PANTG having a lipid metabolic role included ACC, ACLY, CD36, CYP7A1, FASN and SCD1. Central to the differentially expressed proteins involved in lipid metabolism was the predicted activation of the liver X receptor (LXR) pathway. Western analysis validated the increased hepatic expression of LXRα along with LXR-directed targets such as FASN and CYP7A1 within the PANTG liver. Furthermore, recombinant PANDER was capable of inducing LXR promoter activity in-vitro as determined by luciferase reporter assays. Taken together, PANDER strongly impacts hepatic lipid metabolism across metabolic states and may induce a SHIR phenotype via the LXR pathway.

Hepatic nutrient and hormonal regulation of the PANcreatic-DERived factor (PANDER) promoter.

PANcreatic-DERived factor (PANDER, FAM3B) has been shown to regulate glycemic levels via interactions with both pancreatic islets and the liver. Although PANDER is predominantly expressed from the endocrine pancreas, recent work has provided sufficient evidence that the liver may also be an additional tissue source of PANDER production. At physiological levels, PANDER is capable of disrupting insulin signaling and promoting increased hepatic glucose production. As shown in some animal models, strong expression of PANDER, induced by viral delivery within the liver, induces hepatic steatosis. However, no studies to date have explicitly characterized the transcriptional regulation of PANDER from the liver. Therefore, our investigation elucidated the nutrient and hormonal regulation of the hepatic PANDER promoter. Initial RNA-ligated rapid amplification of cDNA ends identified a novel transcription start site (TSS) approximately 26 bp upstream of the PANDER translational start codon not previously revealed in pancreatic ß-cell lines. Western evaluation of various murine tissues demonstrated robust expression in the liver and brain. Promoter analysis identified strong tissue-specific activity of the PANDER promoter in both human and murine liver-derived cell lines. The minimal element responsible for maximal promoter activity within hepatic cell lines was located between -293 and -3 of the identified TSS. PANDER promoter activity was inhibited by both insulin and palmitate, whereas glucose strongly increased expression. The minimal element was responsible for maximal glucose-responsive and basal activity. Co-transfection reporter assays, chromatin-immunoprecipitation (ChIP) and site-directed mutagenesis revealed that the carbohydrate-responsive element binding protein (ChREBP) increased PANDER promoter activity and interacted with the PANDER promoter. E-box 3 was shown to be critical for basal and glucose responsive expression. In summary, in-vitro and in-vivo glucose is a potent stimulator of the PANDER promoter within the liver and this response may be facilitated by ChREBP.

Enhanced glucose tolerance in pancreatic-derived factor (PANDER) knockout C57BL/6 mice.

Pancreatic-derived factor (PANDER; also known as FAM3B) is a uniquely structured protein strongly expressed within and secreted from the endocrine pancreas. PANDER has been hypothesized to regulate fasting and fed glucose homeostasis, hepatic lipogenesis and insulin signaling, and to serve a potential role in the onset or progression of type 2 diabetes (T2D). Despite having potentially pivotal pleiotropic roles in glycemic regulation and T2D, there has been limited generation of stable animal models for the investigation of PANDER function, and there are no models on well-established genetic murine backgrounds for T2D. Our aim was to generate an enhanced murine model to further elucidate the biological function of PANDER. Therefore, a pure-bred PANDER knockout C57BL/6 (PANKO-C57) model was created and phenotypically characterized with respect to glycemic regulation and hepatic insulin signaling. The PANKO-C57 model exhibited an enhanced metabolic phenotype, particularly with regard to enhanced glucose tolerance. Male PANKO-C57 mice displayed decreased fasting plasma insulin and C-peptide levels, whereas leptin levels were increased as compared with matched C57BL/6J wild-type mice. Despite similar peripheral insulin sensitivity between both groups, hepatic insulin signaling was significantly increased during fasting conditions, as demonstrated by increased phosphorylation of hepatic PKB/Akt and AMPK, along with mature SREBP-1 expression. Insulin stimulation of PANKO-C57 mice resulted in increased hepatic triglyceride and glycogen content as compared with wild-type C57BL/6 mice. In summary, the PANKO-C57 mouse represents a suitable model for the investigation of PANDER in multiple metabolic states and provides an additional tool to elucidate the biological function and potential role in T2D.