Islet inflammation, hemosiderosis, and fibrosis in intrauterine growth-restricted and high fat-fed Sprague-Dawley rats.

Prenatal and postnatal factors such as intrauterine growth restriction (IUGR) and high-fat (HF) diet contribute to type 2 diabetes. Our aim was to determine whether IUGR and HF diets interact in type 2 diabetes pathogenesis, with particular attention focused on pancreatic islet morphology including assessment for inflammation. A surgical model of IUGR (bilateral uterine artery ligation) in Sprague-Dawley rats with sham controls was used. Pups were fed either HF or chow diets after weaning. Serial measures of body weight and glucose tolerance were performed. At 25 weeks of age, rat pancreases were harvested for histologic assessment. The birth weight of IUGR pups was 13% lower than that of sham pups. HF diet caused excess weight gain, dyslipidemia, hyperinsulinemia, and mild glucose intolerance, however, this was not aggravated further by IUGR. Markedly abnormal islet morphology was evident in 0 of 6 sham-chow, 5 of 8 sham-HF, 4 of 8 IUGR-chow, and 8 of 9 IUGR-HF rats (chi-square, P = 0.007). Abnormal islets were characterized by larger size, irregular shape, inflammation with CD68-positive cells, marked fibrosis, and hemosiderosis. ß-Cell mass was not altered by IUGR. In conclusion, HF and IUGR independently contribute to islet injury characterized by inflammation, hemosiderosis, and fibrosis. This suggests that both HF and IUGR can induce islet injury via converging pathways. The potential pathogenic or permissive role of iron in this process of islet inflammation warrants further investigation.

Altered decidual DC-SIGN+ antigen-presenting cells and impaired regulatory T-cell induction in preeclampsia.

Regulatory T (Treg) cell expansion is required for tolerance of the semi-allogeneic fetus in healthy pregnancy and impaired in preeclampsia in humans. However, the reasons remain unknown. Herein, we show that expansion of CD4(+)Helios(-)Foxp3(+) adaptive Treg (iTreg) cells, rather than CD4(+)Helios(+)Foxp3(+) natural Treg cells, accounts for this expansion in healthy pregnancy. This expansion is even more pronounced in the decidua, where there is an overrepresentation of iTreg cells. In preeclampsia, however, there is impaired systemic iTreg cell expansion, associated with a lack of iTreg cell overrepresentation in the decidua. Because decidual antigen-presenting cells (APCs) may be important for iTreg cell induction, we studied decidual CD14(+) APCs using immunohistochemistry and flow cytometry. We show that decidual CD14(+)DC-SIGN(+) APCs are closely associated with Foxp3(+) Treg cells. Furthermore, CD14(+)DC-SIGN(+) cells display a distinct phenotype compared with their CD14(+)DC-SIGN(-) counterparts. In particular, they have increased expression of tolerogenic molecules, HLA-G, and immunoglobulin-like transcript 4. In vitro, CD14(+)DC-SIGN(+) APCs from healthy pregnant women induced iTreg cells significantly more efficiently than CD14(+)DC-SIGN(-) APCs. Conversely, in preeclampsia, both CD14(+)DC-SIGN(+) and CD14(+)DC-SIGN(-) APCs induced iTreg cells poorly. These results suggest that decidual CD14(+)DC-SIGN(+) APCs may play important roles in iTreg cell induction, a process that is defective in preeclampsia and likely contributes to its pathogenesis.

Prognostic value of LINE-1 retrotransposon expression and its subcellular localization in breast cancer.

Long interspersed nuclear element 1 (L1) belongs to a family of retrotransposons. Expression of the normally repressed L1 retrotransposons has been shown to induce genome instability by creating DNA double-stranded breaks and chromosomal rearrangements through the process of retrotransposition. At present, little is known about the expression of L1-encoded ORF1p and ORF2p which are indispensable for its retrotransposition activity. Given its potentially harmful effects on the genome, we investigated the implications of both ORF1p and ORF2p expression and their subcellular localization in a range of breast cancer cell lines and breast tumor tissues including 15 normal breast tissues, 25 fibroadenomas, 25 ductal carcinomas in situ (DCIS), and 95 invasive cancers. Clinicopathologic parameters and survival outcomes were investigated in association with the cytoplasmic and nuclear expression of ORF1p and ORF2p using univariate and multivariate analysis. High cytoplasmic expression of ORF1p and ORF2p was seen in DCIS tumors, but they were not related with survival outcome. The majority of invasive cancers were found to express both ORF1p and ORF2p in the cytoplasm, while nuclear expression was also seen in a subclass of those invasive cancers in the range of 28-31 %. Tumors with high nuclear expression of ORF1p and ORF2p were more significantly associated with lymph node metastasis (p = 0.001) and the worst patient survival (p < 0.0001) than those with cytoplasmic expression. This is the first study examining the effects of both ORF1p and ORF2p expression in breast cancer tissues. Our observation shows altered expression patterns of ORF1p and ORF2p within invasive cancers, which are related to differences in overall patient survival. The differing patterns of both cytoplasmic and nuclear ORF1p and ORF2p expression indicate that further studies of the biology and function of L1 retrotransposons are required in breast cancer.