Probes for INS

The uptake of glucose is mediated mainly by the sodium-glucose cotransporter, SGLT1. Previous studies using quantitative PCR showed that SGLT1 mRNA was induced in the yolk sac and in the small intestine prior to hatch. However, PCR analysis did not allow for the localization of cells expressing SGLT1 mRNA. The objective of this study was to use in situ hybridization to identify cells in the yolk sac and small intestine that expressed SGLT1 mRNA during the transition from late embryogenesis to early post-hatch. Expression of SGLT1 mRNA in yolk sac epithelial cells was low from embryonic d 11 to 17, peaked at embryonic d 19, and declined at day of hatch. In the small intestine, cells expressing SGLT1 mRNA were present not only along the intestinal villi but also in the crypts. There was greater expression of SGLT1 mRNA in the intestinal epithelial cells that line the villus than in the olfactomedin 4-expressing stem cells located in the crypts. The latter result suggests that stem cells have the ability to import glucose. Expression of SGLT1 mRNA in the intestine increased from embryonic d 19 to day of hatch and then maintained a high level of expression from d 1 to d 7 post-hatch. For both the yolk sac and small intestine, the temporal pattern of SGLT1 mRNA expression detected by in situ hybridization was consistent with the pattern revealed by PCR.

Abstract

Oncocytic (Hürthle cell) and follicular neoplasms are related thyroid tumors with distinct molecular profiles. Diagnostic criteria separating adenomas and carcinomas for these two types of neoplasms are similar, but there may be some differences in the biological behavior of Hürthle cell and follicular carcinomas. Recent studies have shown that noncoding RNAs may have diagnostic and prognostic utility in separating benign and malignant Hürthle cell and follicular neoplasms. In this study, we examined expression of various noncoding RNAs including metastasis associated lung adenocarcinoma transcript 1 (MALAT1) and miR-RNA-885-5p (miR-885) in distinguishing between benign and malignant neoplasms. In addition, the expression of phosphorylated mechanistic receptor of rapamycin (p-mTOR) was also analyzed in these two groups of tumors. Tissue microarrays (TMAs) with archived tissue samples were analyzed using in situ hybridization (ISH) for MALAT1 and miR-885 and immunohistochemistry (IHC) for p-mTOR. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was also performed on a subset of the cases.MALAT1 and miR-885 were increased in all neoplastic groups compared to the normal thyroid tissues (p < 0.05). MALAT1 was more highly expressed in HCCs compared to FTCs, although the differences were not statistically significant (p = 0.06). MiR-885 was expressed at similar levels in FTCs and HCCs. P-mTOR protein was more highly expressed in FTCs than in HCCs (p<0.001). qRT-PCR analysis of noncoding RNAs supported the ISH findings. These results indicate that the noncoding RNAs MALAT1 and miR-885 show increased expression in neoplastic follicular and Hürthle cell thyroid neoplasms compared to normal thyroid tissues. P-mTOR was most highly expressed in FTC but was also increased in HCC, suggesting that drugs targeting this pathway may be useful for treatment of tumors unresponsive to conventional therapies.

The initiation of spontaneous breast cancer (SBC) in Tientsin Albino 2 (TA2) mice is related to mouse mammary tumor virus (MMTV) infection, and MMTV amplification is hormonally regulated. To explore the insertion site of MMTVLTR in TA2 mouse genome, reverse PCR and nested PCR were used to amplify the unknown sequence on both sides of the MMTV-LTRSAG gene in SBC and normal breast tissue of TA2 mice. Furthermore, the clinicopathological significance of the insertion site was evaluated in 43 samples of normal breast tissue, 46 samples of breast cystic hyperplasia, 54 samples of ductal carcinoma in situ, 142 samples of primary breast cancer and 47 samples of lymph node metastatic breast cancer by RNA in situ hybridization. We confirmed that the insertion site of the MMTV-LTRSAG gene was located between Igκv2-112 and Igκv14-111 in chromosome 6 of TA2 mouse. IGκC was localized in the stromal cells of TA2 mouse with SBC and in human breast cancer tissues. Tumor cells were negative for IGκC in RNA in situ hybridization. The positive staining index of IGκC in stromal cells was the highest in lymph node metastatic breast cancer, followed by primary breast cancer, ductal carcinoma in situ, and breast cystic hyperplasia. Furthermore, the positive staining index of IGκC was related to the expression of ER, PR, HER2 and Ki-67. Our findings showed that stromal IGκC expression was associated with the initiation of SBC in TA2 mice. IGκC may be a high-risk factor for the initiation and progression of human breast cancer.

Recessive Stargardt disease (STGD1) is an inherited blinding disorder caused by mutations in the Abca4 gene. ABCA4 is a flippase in photoreceptor outer segments (OS) that translocates retinaldehyde conjugated to phosphatidylethanolamine across OS disc membranes. Loss of ABCA4 in Abca4 -/- mice and STGD1 patients causes buildup of lipofuscin in the retinal pigment epithelium (RPE) and degeneration of photoreceptors, leading to blindness. No effective treatment currently exists for STGD1. Here we show by several approaches that ABCA4 is additionally expressed in RPE cells. (i) By in situ hybridization analysis and by RNA-sequencing analysis, we show the Abca4 mRNA is expressed in human and mouse RPE cells. (ii) By quantitative immunoblotting, we show that the level of ABCA4 protein in homogenates of wild-type mouse RPE is about 1% of the level in neural retina homogenates. (iii) ABCA4 immunofluorescence is present in RPE cells of wild-type and Mertk -/- but not Abca4 -/- mouse retina sections, where it colocalizes with endolysosomal proteins. To elucidate the role of ABCA4 in RPE cells, we generated a line of genetically modified mice that express ABCA4 in RPE cells but not in photoreceptors. Mice from this line on the Abca4 -/- background showed partial rescue of photoreceptor degeneration and decreased lipofuscin accumulation compared with nontransgenic Abca4 -/- mice. We propose that ABCA4 functions to recycle retinaldehyde released during proteolysis of rhodopsin in RPE endolysosomes following daily phagocytosis of distal photoreceptor OS. ABCA4 deficiency in the RPE may play a role in the pathogenesis of STGD1.