Suboptimal nutrition during prenatal and early postnatal development is associated with increased risk for type 2 diabetes during adult life. A hallmark of such diabetes risk is altered body composition, including reduced lean mass and increased adiposity. Since stem cell number and activity are important determinants of muscle mass, modulation of perinatal nutrition could alter stem cell number/function, potentially mediating developmentally programmed reductions in muscle mass. Skeletal muscle precursors (SMP) were purified from muscle of mice subjected to prenatal undernutrition and/or early postnatal high-fat diet (HFD)-experimental models that are both associated with obesity and diabetes risk. SMP number was determined by flow cytometry, proliferative capacity measured in vitro, and regenerative capacity of these cells determined in vivo after muscle freeze injury. Prenatally undernutrition (UN) mice showed significantly reduced SMP frequencies [Control (C) 4.8% -0.3% (% live cells) vs. UN 3.2% -0.4%, P = 0.015] at 6 weeks; proliferative capacity was unaltered. Reduced SMP in UN was associated with 32% decrease in regeneration after injury (C 16% -3% of injured area vs. UN 11% -2%; P < 0.0001). SMP frequency was also reduced in HFD-fed mice (chow 6.4% -0.6% vs. HFD 4.7% -0.4%, P = 0.03), and associated with 44% decreased regeneration (chow 16% -2.7% vs. HFD 9% -2.2%; P < 0.0001). Prenatal undernutrition was additive with postnatal HFD. Thus, both prenatal undernutrition and postnatal overnutrition reduce myogenic stem cell frequency and function, indicating that developmentally established differences in muscleresident stem cell populations may provoke reductions in muscle mass and repair and contribute to diabetes risk.

OBJECTIVE To characterize the hormonal milieu and adipose gene expression in response to catch-up growth (CUG), a growth pattern associated with obesity and diabetes risk, in a mouse model of low birth weight (LBW). RESEARCH DESIGN AND METHODS ICR mice were food restricted by 50% from gestational days 12.5–18.5, reducing offspring birth weight by 25%. During the suckling period, dams were either fed ad libitum, permitting CUG in offspring, or food restricted, preventing CUG. Offspring were killed at age 3 weeks, and gonadal fat was removed for RNA extraction, array analysis, RT-PCR, and evaluation of cell size and number. Serum insulin, thyroxine (T4), corticosterone, and adipokines were measured. RESULTS At age 3 weeks, LBW mice with CUG (designated U-C) had body weight comparable with controls (designated C-C); weight was reduced by 49% in LBW mice without CUG (designated U-U). Adiposity was altered by postnatal nutrition, with gonadal fat increased by 50% in U-C and decreased by 58% in U-U mice ( P < 0.05 vs. C-C mice). Adipose expression of the lipogenic genes Fasn , Acc I, Lpin1 , and Srebf1 was significantly increased in U-C compared with both C-C and U-U mice ( P < 0.05). Mitochondrial DNA copy number was reduced by >50% in U-C versus U-U mice ( P = 0.014). Although cell numbers did not differ, mean adipocyte diameter was increased in U-C and reduced in U-U mice ( P < 0.01). CONCLUSIONS CUG results in increased adipose tissue lipogenic gene expression and adipocyte diameter but not increased cellularity, suggesting that catch-up fat is primarily associated with lipogenesis rather than adipogenesis in this murine model.

Maternal obesity and gestational diabetes mellitus (GDM) are associated with obesity and diabetes risk in offspring. We tested whether maternal insulin resistance, which frequently coexists with GDM and obesity, could independently contribute to dysregulation of offspring metabolism. Female mice haploinsufficient for insulin receptor substrate-1 (IRS1-het) are hyperinsulinemic and insulin resistant during pregnancy, despite normal plasma glucose and body weight, and thus serve as a model of isolated maternal insulin resistance. Wild-type (WT) offspring of IRS1-het dams insulin resistance-exposed [IR-exposed] were compared with WT offspring of WT dams. Despite no differences in adiposity, male IR-exposed pups were glucose intolerant (P = 0.04) and hyperinsulinemic (1.3-fold increase, P = 0.02) by 1 month of age and developed progressive fasting hyperglycemia. Moreover, male IR-exposed pups challenged with high-fat diet exhibited insulin resistance. Liver lipidomic analysis of 3-week-old IR-exposed males revealed increases in the 16:1n7 fraction of several lipid classes, suggesting increased Scd1 activity. By 6 months of age, IR-exposed males had increased lipid accumulation in liver as well as increased plasma refed fatty acids, consistent with disrupted lipid metabolism. Our results indicate that isolated maternal insulin resistance, even in the absence of hyperglycemia or obesity, can promote metabolic perturbations in male offspring.

Twenty-two apparently euthyroid patients with endocrine ophthalmopathy not associated with goiter, antithyroid microsomal or antithyroglobulin antibodies, or overt thyroid disease (so-called ophthalmic Graves' disease) were tested for subclinical hyperthyroidism or hypothyroidism. We measured 131I uptake and scan, serum T3 (by RIA), and serum TSH using a sensitive (by immunoradiometric assay) assay. Three patients were found to be hyperthyroid, and 1 was hypothyroid. The remaining 18 patients, who remained euthyroid throughout the study period, were investigated for evidence for antibody-mediated immunity against thyroid antigens. We measured antibody-dependent cell-mediated cytotoxicity against fresh thyroid cells using a 51chromium release assay, thyroid membrane-reactive antibodies in an enzyme-linked immunosorbent assay incorporating solubilized thyroid membranes, and TSH receptor-binding antibodies using a RRA and carried out sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting with patient sera for antibodies reactive with 64 and 110 kDa (thyroid peroxidase) membrane proteins. Bands were demonstrated, on SDS-PAGE, at 64 or 110 kDa in 13 patients, antibody-dependent cell-mediated cytotoxicity tests were positive in 7 patients, and enzyme-linked immunosorbent assay was positive in 4 of the 17 patients tested. In addition, TSH receptor antibody tests were positive in 5 patients, none of whom had other evidence for hyperthyroidism. Finally, significant lymphocyte infiltration was demonstrated on aspiration biopsy in 3 patients. All 18 patients had positive tests in at least 1 of the immunological assays. We believe that these data support the hypothesis that endocrine ophthalmopathy always occurs in patients with overt or subclinical Graves' hyperthyroidism, Hashimoto's thyroiditis, or thyroid immunological abnormalities. Those patients previously described as having euthyroid Graves' disease should, thus, be considered to have associated thyroid immunological abnormalities even though histological confirmation (from aspiration needle biopsy) may be obtained in only a minority of the patients. The possibility that the mechanism for this close association is cross-reactivity of cytotoxic antibodies against a thyroid/eye muscle cell surface shared antigen is discussed in the context of recent evidence from the authors' laboratory.

Both intrauterine and postnatal environments contribute to diabetes risk. A recent paper highlights epigenetic mechanisms underlying beta cell dysfunction associated with intrauterine growth retardation, including repressive histone modification and DNA methylation during postnatal life. Thus, intrauterine stress can initiate a disturbing epigenetic cascade of progressive transcriptional repression linked to beta cell failure.

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related deaths in the United States by 2020, due in part to innate resistance to widely used chemotherapeutic agents and limited knowledge about key molecular factors that drive tumor aggression. We previously reported a novel negative prognostic biomarker, keratin 17 (K17), whose overexpression in cancer results in shortened patient survival. In this study, we aimed to determine the predictive value of K17 and explore the therapeutic vulnerability in K17-expressing PDAC, using an unbiased high-throughput drug screen. Patient-derived data analysis showed that K17 expression correlates with resistance to Gemcitabine (Gem). In multiple in vitro models of PDAC, spanning human and murine PDAC cells, we determined that the expression of K17 results in a more than twofold increase in resistance to Gem and 5-fluorouracil, key components of current standard-of-care chemotherapeutic regimens. Furthermore, through an unbiased drug screen, we discovered that Podophyllotoxin (PPT), a microtubule inhibitor, showed at least two-fold higher sensitivity in K17expressing compared to K17-negative PDAC cells. In the clinic, another microtubule inhibitor, Paclitaxel (PTX), is used in combination with Gem as a first line chemotherapeutic regimen for pancreatic, breast, lung, and ovarian cancer. Surprisingly, we found that when combined with Gem, PPT but not PTX, was synergistic in inhibiting the viability of K17-expressing PDAC cells. This provides evidence that PPT or its derivatives could potentially be combined with Gem to enhance treatment efficacy for the approximately 50% of PDACs that express high levels of K17. In summary, we reported that K17 is a novel target for developing a biomarker-based personalized treatment for PDAC.3 4 2. Methods 2.1. Predictive-value analyses from patient-derived samples K17 mRNA expression levels of PDAC cases were acquired from the Australian Pancreatic Cancer Genome Initiative (APGI)13. K17 mRNA expression and survival were evaluated in 94 PDAC patients that were treated with adjuvant Gem alone or received no treatment. Based on the established cutoff of the maximum likelihood fit of a Cox proportional hazard model15, we applied the 76th percentile of mRNA expression to categorize patients into high-K17 versus low-K17 groups. Overall survival in high-versus low-K17 mRNA was determined using the Kaplan-Meier method, calculated from the date of diagnosis to the date of death. Patients still alive at the last follow-up were censored. Prognostic and predictive analyses were performed based on the criteria described by Ballman18. Adjusting for potential confounders, a multivariate analysis was performed by Cox proportional hazard regression. Statistical significance was set at p<0.05 and analysis was done using SAS 9.4 (SAS Institute) and GraphPad Prism 7 (Graph Pad Software). Compounds testedGem (purity > 99%), 5-FU (purity > 99%), Podophyllotoxin (PPT, purity > 99%), Taxol (PTX, purity > 95%), Mitoxant...

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer‐related deaths in the United States by 2020, due in part to innate resistance to widely used chemotherapeutic agents and limited knowledge about key molecular factors that drive tumor aggression. We previously reported a novel negative prognostic biomarker, keratin 17 (K17), whose overexpression in cancer results in shortened patient survival. In this study, we aimed to determine the predictive value of K17 and explore the therapeutic vulnerability in K17‐expressing PDAC, using an unbiased high‐throughput drug screen. Patient‐derived data analysis showed that K17 expression correlates with resistance to gemcitabine (Gem). In multiple in vitro and in vivo models of PDAC, spanning human and murine PDAC cells, and orthotopic xenografts, we determined that the expression of K17 results in a more than twofold increase in resistance to Gem and 5‐fluorouracil, key components of current standard‐of‐care chemotherapeutic regimens. Furthermore, through an unbiased drug screen, we discovered that podophyllotoxin (PPT), a microtubule inhibitor, showed significantly higher sensitivity in K17‐positive compared to K17‐negative PDAC cell lines and animal models. In the clinic, another microtubule inhibitor, paclitaxel (PTX), is used in combination with Gem as a first‐line chemotherapeutic regimen for PDAC. Surprisingly, we found that when combined with Gem, PPT, but not PTX, was synergistic in inhibiting the viability of K17‐expressing PDAC cells. Importantly, in preclinical models, PPT in combination with Gem effectively decreased tumor growth and enhanced the survival of mice bearing K17‐expressing tumors. This provides evidence that PPT and its derivatives could potentially be combined with Gem to enhance treatment efficacy for the ~ 50% of PDACs that express high levels of K17. In summary, we reported that K17 is a novel target for developing a biomarker‐based personalized treatment for PDAC.

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