SUMMARY Chronic pancreatitis is a well-known risk factor for pancreatic ductal adenocarcinoma (PDA) development in humans, and inflammation promotes PDA initiation and progression in mouse models of the disease. However, the mechanistic link between inflammatory damage and PDA initiation is unclear. Using a Kras-driven mouse model of PDA, we establish that the inflammatory mediator Stat3 is a critical component of spontaneous and pancreatitis-accelerated PDA precursor formation and supports cell proliferation, metaplasia associated inflammation, and MMP7 expression during neoplastic development. Furthermore, we show that Stat3 signaling enforces MMP7 expression in PDA cells and that MMP7 deletion limits tumor size and metastasis in mice. Finally, we demonstrate that serum MMP7 level in human PDA patients correlated with metastatic disease and survival.

Summary Extrinsic signals controlling generation of neocortical neurons during embryonic life have been difficult to identify. In this study we demonstrate that the dorsal forebrain meninges communicate with the adjacent radial glial endfeet and influence cortical development. We took advantage of Foxc1 mutant mice with defects in forebrain meningeal formation. Foxc1 dosage and loss of meninges correlated with a dramatic reduction in both neuron and intermediate progenitor production and elongation of the neuroepithelium. Several types of experiments demonstrate that retinoic acid (RA) is the key component of this secreted activity. In addition, Rdh10 and Raldh2 expressing cells in the dorsal meninges were either reduced or absent in the Foxc1 mutants and Rdh10 mutants had a cortical phenotype similar to the Foxc1-null mutants. Lastly, in utero RA treatment rescued the cortical phenotype in Foxc1 mutants. These results establish RA as a potent, meningeal-derived cue required for successful corticogenesis.

We report an improved tandem mass spectrometric assay for retinoic acid (RA) applicable to in vitro and in vivo biological samples. This liquid chromatography tandem mass spectrometric (LC/MS/MS) assay for direct RA quantification is the most sensitive to date, with a 62.5 attomol lower limit of detection and a linear range spanning greater than 4 orders of magnitude (from 250 attomol to 10 pmol). This assay resolves all-trans-RA (atRA) from its endogenous geometric isomers, is applicable to samples of limited size (10-20 mg of tissue), and functions with complex biological matrixes. Coefficients of variation are as follows: instrumental, ≤2.6%; intraday, 5.2% ± 0.7%; interday, 6.7% ± 0.9%. In vitro capabilities are demonstrated by quantification of endogenous RA and RA production (from retinol) in primary cultured astrocytes. Quantification of endogenous atRA and its geometric isomers in 129SV mouse serum and tissues (liver, kidney, adipose, muscle, spleen, testis, and brain) reveals in vivo utility of the assay. The ability to discriminate spatial concentrations of RA in vivo is illustrated with C57BL/6 mouse brain loci (hippocampus, cortex, olfactory bulb, thalamus, cerebellum, and striatum), as well as with Lewis rat proximal/distal mammary gland regions during various morphological stages: virgin, early pregnancy (e7), late pregnancy (e20), lactating (day 4), involuting day 1, and involuting day 11. This assay provides the sensitivity necessary for direct, endogenous RA quantification necessary to elucidate RA function, e.g., in neurogenesis, morphogenesis, and the contribution of altered RA homeostasis to diseases, such as Alzheimer's disease, type 2 diabetes, obesity, and cancer.Metabolism activates vitamin A (retinol) into retinoic acid (RA), which controls physiological processes including development, nervous system function, immune response, cell proliferation and differentiation, and reproduction. 1-3 Expression loci of retinoidspecific binding proteins, enzymes, and receptors that contribute to RA generation, signaling, and catabolism indicate that RA concentrations in vivo are temporally/spatially controlled to produce the individual actions of vitamin A. [4][5][6][7][8] Recent investigations have linked alterations in retinoid metabolism to aberrant neurogenesis, aberrant mammary gland morphogenesis, and to diseases, including Alzheimer's disease, type 2 diabetes, obesity, and cancer. 9-14 These studies and others postulate alterations in RA as mechanistically important but have not quantified RA directly. Therefore, analytically rigorous measurements capable of sensitively discriminating changes in endogenous RA levels either Here we report an improved and versatile method for direct quantification of atRA and its isomers in cultured cells, serum, and tissues with increased sensitivity and greater facility to monitor retinoid metabolism in vitro and in vivo. This assay provides the best sensitivity to date for quantifying RA and could be adapted to monitor RA metabolites. EXPERIMENTAL SEC...

IN BRIEF This study quantitatively measures diabetes stigma and its associated psychosocial impact in a large population of U.S. patients with type 1 or type 2 diabetes using an online survey sent to 12,000 people with diabetes. A majority of respondents with type 1 (76%) or type 2 (52%) diabetes reported that diabetes comes with stigma. Perceptions of stigma were significantly higher among respondents with type 1 diabetes than among those with type 2 diabetes, with the highest rate in parents of children with type 1 diabetes (83%) and the lowest rate in people with type 2 diabetes who did not use insulin (49%). Our results suggest that a disturbingly high percentage of people with diabetes experience stigma, particularly those with type 1 or type 2 diabetes who are on intensive insulin therapy. The experience of stigma disproportionately affects those with a higher BMI, higher A1C, and poorer self-reported blood glucose control, suggesting that those who need the most help are also the most affected by stigma.

We report robust HPLC/UV methods for quantifying retinyl esters (RE), retinol (ROL) and retinal (RAL) applicable to diverse biological samples, with lower limits of detection of 0.7 pmol, 0.2 pmol, and 0.2 pmol, respectively, and linear ranges >3 orders of magnitude. These assays function well with small, complex biological samples (10-20 mg tissue). Coefficients of variation range from: intra-day, 5.9-10.0%; inter-day, 5.9-11.0%. Quantification of endogenous RE, ROL, and RAL in mouse serum and tissues (liver, kidney, adipose, muscle, spleen, testis, skin, brain, and brain regions) reveals utility. Ability to discriminate spatial concentrations of ROL and RE is illustrated with C57BL/6 mouse brain loci (hippocampus, cortex, olfactory bulb, thalamus, cerebellum, and striatum.) We also developed a method to distinguish isomeric forms of ROL to investigate precursors of retinoic acid. The ROL isomer assay has limits of detection between 3.5-4.5 pmol and a similar linear range and % CV as the ROL/RE and RAL assays. The assays described here provide for sensitive and rigorous quantification of endogenous RE, ROL, and RAL to elucidate retinoid homeostasis in disease states, such as Alzheimer's disease, type 2 diabetes, obesity, and cancer.