Hyperpolarized [1-13 C] pyruvate MRSI to detect metabolic changes in liver in a methionine and choline-deficient diet rat model of fatty liver disease.

PURPOSE: Nonalcoholic fatty liver disease is an important cause of chronic liver disease. There are limited methods for monitoring metabolic changes during progression to steatohepatitis. Hyperpolarized 13 C MRSI (HP 13 C MRSI) was used to measure metabolic changes in a rodent model of fatty liver disease. METHODS: Fifteen Wistar rats were placed on a methionine- and choline-deficient (MCD) diet for 1-18 weeks. HP 13 C MRSI, T2 -weighted imaging, and fat-fraction measurements were obtained at 3 T. Serum aspartate aminotransaminase, alanine aminotransaminase, and triglycerides were measured. Animals were sacrificed for histology and measurement of tissue lactate dehydrogenase (LDH) activity. RESULTS: Animals lost significant weight (13.6% ± 2.34%), an expected characteristic of the MCD diet. Steatosis, inflammation, and mild fibrosis were observed. Liver fat fraction was 31.7% ± 4.5% after 4 weeks and 22.2% ± 4.3% after 9 weeks. Lactate-to-pyruvate and alanine-to-pyruvate ratios decreased significantly over the study course; were negatively correlated with aspartate aminotransaminase and alanine aminotransaminase (r = -[0.39-0.61]); and were positively correlated with triglycerides (r = 0.59-0.60). Despite observed decreases in hyperpolarized lactate signal, LDH activity increased by a factor of 3 in MCD diet-fed animals. Observed decreases in lactate and alanine hyperpolarized signals on the MCD diet stand in contrast to other studies of liver injury, where lactate and alanine increased. Observed hyperpolarized metabolite changes were not explained by alterations in LDH activity, suggesting that changes may reflect co-factor depletion known to occur as a result of oxidative stress in the MCD diet. CONCLUSION: HP 13 C MRSI can noninvasively measure metabolic changes in the MCD model of chronic liver disease.

Self-Assembled Matrigel-Free iPSC-Derived Liver Organoids Demonstrate Wide-Ranging Highly Differentiated Liver Functions.

Human induced pluripotent stem cell (iPSC)-derived liver organoids serve as models of organogenesis, disease, drug screening, and regenerative medicine. Prevailing methods for generating organoids rely on Matrigel, whose batch-to-batch variability and xenogeneic source pose challenges to mechanistic research and translation to human clinical therapy. In this report, we demonstrate that self-assembled Matrigel-free iPSC-derived organoids developed in rotating wall vessels (RWVs) exhibit greater hepatocyte-specific functions than organoids formed on Matrigel. We show that RWVs produce highly functional liver organoids in part by eliminating the need for Matrigel, which has adverse effects on hepatic lineage differentiation. RWV liver organoids sustain durable function over long-term culture and express a range of mature functional genes at levels comparable to adult human liver, while retaining some fetal features. Our results indicate that RWVs provide a simple and high-throughput way to generate Matrigel-free liver organoids suitable for research and clinical applications.

De novo formation of the biliary system by TGFß-mediated hepatocyte transdifferentiation.

Transdifferentiation is a complete and stable change in cell identity that serves as an alternative to stem-cell-mediated organ regeneration. In adult mammals, findings of transdifferentiation have been limited to the replenishment of cells lost from preexisting structures, in the presence of a fully developed scaffold and niche1. Here we show that transdifferentiation of hepatocytes in the mouse liver can build a structure that failed to form in development-the biliary system in a mouse model that mimics the hepatic phenotype of human Alagille syndrome (ALGS)2. In these mice, hepatocytes convert into mature cholangiocytes and form bile ducts that are effective in draining bile and persist after the cholestatic liver injury is reversed, consistent with transdifferentiation. These findings redefine hepatocyte plasticity, which appeared to be limited to metaplasia, that is, incomplete and transient biliary differentiation as an adaptation to cell injury, based on previous studies in mice with a fully developed biliary system3-6. In contrast to bile duct development7-9, we show that de novo bile duct formation by hepatocyte transdifferentiation is independent of NOTCH signalling. We identify TGFß signalling as the driver of this compensatory mechanism and show that it is active in some patients with ALGS. Furthermore, we show that TGFß signalling can be targeted to enhance the formation of the biliary system from hepatocytes, and that the transdifferentiation-inducing signals and remodelling capacity of the bile-duct-deficient liver can be harnessed with transplanted hepatocytes. Our results define the regenerative potential of mammalian transdifferentiation and reveal opportunities for the treatment of ALGS and other cholestatic liver diseases.

MicroRNAs Associated with Metformin Treatment in the Diabetes Prevention Program.

The Diabetes Prevention Program (DPP) randomized controlled trial demonstrated that metformin treatment reduced progression to type 2 diabetes (T2D) by 31% compared to placebo in adults with prediabetes. Circulating micro-ribonucleic acids (miRs) are promising biomarkers of T2D risk, but little is known about their associations with metformin regimens for T2D risk reduction. We compared the change in 24 circulating miRs from baseline to 2 years in a subset from DPP metformin intervention (n = 50) and placebo (n = 50) groups using Wilcoxon signed rank tests. Spearman correlations were used to evaluate associations between miR change and baseline clinical characteristics. Multiple linear regression was used to adjust for covariates. The sample was 73% female, 17% Black, 13% Hispanic, and 50 ± 11 years. Participants were obese, normotensive, prediabetic, and dyslipidemic. Change in 12 miR levels from baseline to 2 years was significantly different in the metformin group compared with placebo after adjusting for multiple comparisons: six (let-7c-5p, miR-151a-3p, miR-17-5p, miR-20b-5p, miR-29b-3p, and miR-93-5p) were significantly upregulated and six (miR-130b-3p, miR-22-3p, miR-222-3p, miR-320a-3p, miR-320c, miR-92a-3p) were significantly downregulated in the metformin group. These miRs help to explain how metformin is linked to T2D risk reduction, which may lead to novel biomarkers, therapeutics, and precision health strategies.

Fundic Gland Polyps Lack DNA Content Abnormality Characteristic of Other Adenomatous Precursor Lesions in the Gastrointestinal Tract.

Fundic gland polyps (FGPs) develop sporadically (frequently after proton pump inhibitor therapy) or in the setting of a hereditary polyposis syndrome, such as familial adenomatous polyposis (FAP). FAP-related FGPs often demonstrate low-grade dysplasia (LGD) and are frequently associated with APC mutations, even in the absence of dysplasia. Sporadic FGPs with dysplasia are molecularly similar to FAP-related FGPs and demonstrate frequent mutations in APC gene. Despite having similar molecular alterations with colorectal and other adenomatous precursor lesions in the gastrointestinal (GI) tract, FGPs rarely progress to advanced gastric neoplasia (high-grade dysplasia [HGD] or adenocarcinoma), and their role in gastric tumorigenesis remains unclear but likely limited. The clinicopathologic features of 192 patients diagnosed with FGPs, including 86 with FAP-related FGPs (33 with dysplastic FGPs and 53 with nondysplastic FGPs) and 106 with sporadic FGPs (12 with dysplastic FGPs and 94 with nondysplastic FGPs), were analyzed. DNA flow cytometry was performed on 111 FAP-related FGP biopsies, including 32 FGPs with LGD and 79 nondysplastic FGPs, to assess the presence of abnormal DNA content (ie, aneuploidy or elevated 4N fraction). Moreover, 40 sporadic FGP biopsies, including 14 dysplastic (13 LGD and 1 HGD) and 26 nondysplastic FGPs, were examined for DNA content abnormality. Patients with FAP and nondysplastic FGPs were more likely to be younger (mean age, 32 years) and present with multiple FGPs (92%, defined as having ≥2 FGPs) than those with sporadic nondysplastic FGPs (61 years and 65%, respectively; P < .001). They also recorded higher rates of previous or concurrent gastric epithelial dysplasia not occurring in a FGP (8%, P = .016), nongastric GI dysplasia (96%, P < .001), and nongastric GI malignancy (17%, P = .001) compared with those with sporadic nondysplastic FGPs (0%, 52%, and 2%, respectively). The sporadic group was more frequently associated with proton pump inhibitor therapy (78%, P < .001), gastric intestinal metaplasia (24%, P = .004), and a family history of gastric cancer (10%, P = .027) than the FAP group (19%, 6%, and 0%, respectively). Almost all FAP-related FGPs had a polypoid endoscopic appearance (98% vs 84% for sporadic FGPs; P = .009). The mean size of the largest FAP-related FGPs (0.5 cm) was similar to that of sporadic FGPs (0.7 cm) (P = .069). None of the 147 patients with FAP-related or sporadic nondysplastic FGPs were associated with subsequent detection of advanced gastric neoplasia within a mean follow-up time of 54 months (range, <1 to 277 months). However, 2 (4%) of the 45 patients with FAP-related or sporadic dysplastic FGPs developed advanced gastric neoplasia within a mean follow-up time of 59 months (range, <1 to 236 months). One (3%) of the 33 patients with FAP and dysplastic FGPs developed signet ring cell adenocarcinoma, whereas 1 (8%) of the 12 patients with sporadic dysplastic FGPs developed HGD (P = .445). However, none of the FAP-related and sporadic FGP biopsies, regardless of the presence or absence of dysplasia, demonstrated DNA content abnormality. In conclusion, FGPs lack large-scale chromosomal changes that are characteristic of the typical adenoma-carcinoma sequence involved in the development of other GI malignancies. Progression to advanced gastric neoplasia is rare in FGPs, which may be partly explained by the apparent lack of the chromosomal instability phenotype in these lesions.

DNA content abnormality frequently develops in the right/proximal colon in patients with primary sclerosing cholangitis and inflammatory bowel disease and is highly predictive of subsequent detection of dysplasia.

AIMS: Patients with primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD, termed PSC-IBD) have a higher risk of harbouring nonconventional and/or invisible dysplasias, especially in the right/proximal colon, than those with IBD alone. We postulated that DNA content abnormality may be frequently detected in the right/proximal colon in PSC-IBD patients, even in the absence of dysplasia, and that this may predispose to progression to nonconventional and/or invisible dysplasias that are often associated with increased rates of aneuploidy and advanced neoplasia. METHODS AND RESULTS: DNA flow cytometry was performed on 96 morphologically benign colon biopsies taken throughout the colon from 25 PSC-IBD patients during the surveillance colonoscopy that preceded the next procedure that detected dysplasia. Thirty (31%) of the 96 benign colon biopsies in this dysplasia group demonstrated abnormal DNA content, with a propensity for the right/proximal colon (70%) (P < 0.001). In contrast, only one (1%) of 87 benign colon biopsies from 20 IBD patients without neoplasia (control group) demonstrated DNA content abnormality, and it was from the left colon. For analysis per patient, 48% (12 of 25) of the patients in the dysplasia group had abnormal DNA content compared with 5% (1 of 20) of the control group (P = 0.002). Of the 12 PSC-IBD patients with DNA content abnormality, invisible dysplasia was detected in 10 (83%) patients on follow-up, nine (75%) of whom had nonconventional dysplasia. CONCLUSION: PSC-IBD patients have an increased risk of developing abnormal DNA content in the right/proximal colon, predating the detection of dysplasia.

Doxycycline Significantly Enhances Induction of Induced Pluripotent Stem Cells to Endoderm by Enhancing Survival Through Protein Kinase B Phosphorylation.

BACKGROUND AND AIMS: Induced pluripotent stem cells (iPSCs) provide an important tool for the generation of patient-derived cells, including hepatocyte-like cells, by developmental cues through an endoderm intermediate. However, most iPSC lines fail to differentiate into endoderm, with induction resulting in apoptosis. APPROACH AND RESULTS: To address this issue, we built upon published methods to develop an improved protocol. We discovered that doxycycline dramatically enhances the efficiency of iPSCs to endoderm differentiation by inhibiting apoptosis and promoting proliferation through the protein kinase B pathway. We tested this protocol in >70 iPSC lines, 90% of which consistently formed complete sheets of endoderm. Endoderm generated by our method achieves similar transcriptomic profiles, expression of endoderm protein markers, and the ability to be further differentiated to downstream lineages. CONCLUSIONS: Furthermore, this method achieves a 4-fold increase in endoderm cell number and will accelerate studies of human diseases in vitro and facilitate the expansion of iPSC-derived cells for transplantation studies.

Persistent or recurrent Barrett's neoplasia after an endoscopic therapy session is associated with DNA content abnormality and can be detected by DNA flow cytometric analysis of paraffin-embedded tissue.

Endoscopic therapy is currently the standard of care for the treatment of high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) in patients with Barrett's esophagus (BE). Visible lesions are treated with endoscopic mucosal resection (EMR), which is often coupled with radiofrequency ablation (RFA). However, endoscopic therapy may require multiple sessions (one session every 2-3 months) and does not always assure complete eradication of neoplasia. Furthermore, despite complete eradication, recurrences are not uncommon. This study assesses which potential risk factors can predict a poor response after endoscopic sessions. Forty-five BE patients who underwent at least one endoscopic session (EMR alone or ablation with or without preceding EMR) for the treatment of HGD/IMC, low-grade dysplasia (LGD), or indefinite for dysplasia (IND) were analyzed. DNA flow cytometry was performed on 82 formalin-fixed paraffin-embedded samples from the 45 patients, including 78 HGD/IMC, 2 LGD, and 2 IND. Eight non-dysplastic BE samples were used as controls. Three to four 60-micron thick sections were cut from each tissue block, and the area of HGD/IMC, LGD, or IND was manually dissected. Potential associations between clinicopathologic risk factors and persistent/recurrent HGD/IMC following each endoscopic session were examined using univariate and multivariate Cox models with frailty terms. Sixty (73%) of the 82 specimens showed abnormal DNA content (aneuploidy or elevated 4N fraction). These were all specimens with HGD/IMC (representing 77% of that group). Of these 60 HGD/IMC samples with abnormal DNA content, 42 (70%) were associated with subsequent development of persistent/recurrent HGD/IMC (n = 41) or esophageal adenocarcinoma (EAC; n = 1) within a mean follow-up time of 16 months (range: 1 month to 9.4 years). In contrast, only 6 (27%, all HGD/IMC) of the 22 remaining samples (all with normal DNA content) were associated with persistent/recurrent HGD/IMC. For outcome analysis per patient, 11 (24%) of the 45 patients developed persistent/recurrent HGD/IMC or EAC, despite multiple endoscopic sessions (mean: 3.6, range: 1-11). In a univariate Cox model, the presence of abnormal DNA content (hazard ratio [HR] = 3.8, p = 0.007), long BE segment ≥ 3 cm (HR = 3.4, p = 0.002), endoscopic nodularity (HR = 2.5, p = 0.042), and treatment with EMR alone (HR = 2.9, p = 0.006) were significantly associated with an increased risk for persistent/recurrent HGD/IMC or EAC. However, only abnormal DNA content (HR = 6.0, p = 0.003) and treatment with EMR alone (HR = 2.7, p = 0.047) remained as significant risk factors in a multivariate analysis. Age ≥ 60 years, gender, ethnicity, body mass index (BMI) ≥ 30 kg/m2, presence of hiatal hernia, and positive EMR lateral margin for neoplasia were not significant risk factors for persistent/recurrent HGD/IMC or EAC (p > 0.05). Three-month, 6-month, 1-year, 3-year, and 6-year adjusted probabilities of persistent/recurrent HGD/IMC or EAC in the setting of abnormal DNA content were 31%, 56%, 67%, 79%, and 83%, respectively. The corresponding probabilities in the setting of normal DNA content were 10%, 21%, 28%, 38%, and 43%, respectively. In conclusion, in BE patients with baseline HGD/IMC, both DNA content abnormality and treatment with EMR alone were significantly associated with persistent/recurrent HGD/IMC or EAC following each endoscopic session. DNA content abnormality as detected by DNA flow cytometry identifies HGD/IMC patients at highest risk for persistent/recurrent HGD/IMC or EAC, and it also serves as a diagnostic marker of HGD/IMC with an estimated sensitivity of 77%. The diagnosis of HGD/IMC in the setting of abnormal DNA content may warrant alternative treatment strategies as well as long-term follow-up with shorter surveillance intervals.

Non-conventional dysplasia in inflammatory bowel disease is more frequently associated with advanced neoplasia and aneuploidy than conventional dysplasia.

AIMS: Several different non-conventional morphological patterns of epithelial dysplasia have been recently described in inflammatory bowel disease (IBD), but there is limited information regarding their clinicopathological and molecular features, as well as potential risk for high-grade dysplasia (HGD) or colorectal cancer (CRC) compared with conventional dysplasia developing in IBD. METHODS AND RESULTS: A total of 317 dysplastic lesions from 168 IBD patients were analysed. All lesions were re-reviewed and subtyped as either conventional [including tubular adenoma-like (n = 183) and tubulovillous/villous adenoma-like (n = 56)] or non-conventional dysplasia [including dysplasia with increased Paneth cell differentiation (DPD, n = 40), crypt cell dysplasia (CCD, n = 14), goblet cell deficient (GCD, n = 10), hypermucinous (n = 7), sessile serrated lesion (SSL)-like (n = 4) and traditional serrated adenoma (TSA)-like (n = 3)]. DNA flow cytometry was performed on 70 low-grade conventional (n = 24) and non-conventional (n = 46) dysplastic biopsies to determine their malignant potential and molecular pathways to HGD or CRC. Eleven sporadic tubular adenomas with low-grade dysplasia (LGD) were utilised as controls. Seventy-eight non-conventional dysplastic lesions were identified in 56 (33%) of the 168 patients, whereas 239 conventional dysplastic lesions were identified in 149 (89%) patients. Although both non-conventional and conventional dysplasias were most often graded as LGD at diagnosis (83% and 84%, respectively), non-conventional dysplasia (38%) was more likely to develop HGD or CRC in the same colonic segment than conventional dysplasia (19%) on follow-up (P < 0.001). Almost half (46%) of non-conventional dysplastic samples showed aneuploidy, whereas only 8% of conventional dysplasia (P = 0.002) and 9% of sporadic tubular adenomas (P = 0.037) did. Also, non-conventional dysplasia more frequently presented as a flat/invisible lesion (41%) compared with conventional dysplasia (18%) (P < 0.001). Among the non-conventional subtypes (n = 78), DPD was the most common (n = 40; 51%), followed by CCD (n = 14; 18%), GCD (n = 10; 13%), hypermucinous (n = 7; 9%), SSL-like (n = 4; 5%) and TSA-like (n = 3; 4%) variants. Hypermucinous dysplasia (mean = 2.1 cm) was significantly larger than DPD, SSL-like, TSA-like and GCD variants (mean = 1.0, 1.2, 1.2 and 1.9 cm, respectively) (P = 0.037). HGD or CRC was more likely to be associated with CCD (n = 13; 93%), hypermucinous (n = 4; 57%), GCD (n = 4; 40%) and SSL-like (n = 3; 75%) variants than DPD (n = 6; 15%) and TSA-like dysplasia (n = 0; 0%) on follow-up (P < 0.001). Furthermore, the rate of aneuploidy was significantly higher in CCD (100%), hypermucinous (80%) and GCD (25%) variants than in DPD (12%), SSL-like dysplasia (0%) and TSA-like dysplasia (0%) (P < 0.001). CONCLUSIONS: Non-conventional morphological patterns of dysplasia are not uncommon in IBD, detected in 33% of the patients. The higher frequencies of advanced neoplasia (HGD or CRC) and aneuploidy in non-conventional dysplasia, in particular CCD, hypermucinous and GCD variants, suggest that they may have a higher malignant potential than conventional dysplasia or sporadic tubular adenomas, and thus need complete removal and/or careful follow-up. Greater than 40% of non-conventional dysplasia presented as a flat/invisible lesion, suggesting that IBD patients may benefit from random biopsy sampling in addition to targeted biopsies. The majority of non-conventional subtypes appear to develop via the chromosomal instability pathway, whereas an alternative serrated pathway may be responsible for the development of at least a subset of SSL-like and TSA-like dysplasias.

Mouse liver repopulation with hepatocytes generated from human fibroblasts.

Human induced pluripotent stem cells (iPSCs) have the capability of revolutionizing research and therapy of liver diseases by providing a source of hepatocytes for autologous cell therapy and disease modelling. However, despite progress in advancing the differentiation of iPSCs into hepatocytes (iPSC-Heps) in vitro, cells that replicate the ability of human primary adult hepatocytes (aHeps) to proliferate extensively in vivo have not been reported. This deficiency has hampered efforts to recreate human liver diseases in mice, and has cast doubt on the potential of iPSC-Heps for liver cell therapy. The reason is that extensive post-transplant expansion is needed to establish and sustain a therapeutically effective liver cell mass in patients, a lesson learned from clinical trials of aHep transplantation. Here, as a solution to this problem, we report the generation of human fibroblast-derived hepatocytes that can repopulate mouse livers. Unlike current protocols for deriving hepatocytes from human fibroblasts, ours did not generate iPSCs but cut short reprogramming to pluripotency to generate an induced multipotent progenitor cell (iMPC) state from which endoderm progenitor cells and subsequently hepatocytes (iMPC-Heps) could be efficiently differentiated. For this purpose we identified small molecules that aided endoderm and hepatocyte differentiation without compromising proliferation. After transplantation into an immune-deficient mouse model of human liver failure, iMPC-Heps proliferated extensively and acquired levels of hepatocyte function similar to those of aHeps. Unfractionated iMPC-Heps did not form tumours, most probably because they never entered a pluripotent state. Our results establish the feasibility of significant liver repopulation of mice with human hepatocytes generated in vitro, which removes a long-standing roadblock on the path to autologous liver cell therapy.

Diagnosis, risk stratification, and management of ampullary dysplasia by DNA flow cytometric analysis of paraffin-embedded tissue.

The limited accuracy of endoscopic biopsy in detecting high-grade dysplasia or adenocarcinoma within ampullary adenoma or dysplasia has been reported. The natural history of ampullary dysplasia is also unclear, and there are no established guidelines to determine which patients with ampullary dysplasia require resection versus surveillance endoscopy. DNA flow cytometry was performed on 47 ampullary biopsies with low-grade dysplasia, 18 high-grade dysplasia, and 23 negative for dysplasia, as well as 11 cases of ampullary adenocarcinoma. Abnormal DNA content (aneuploidy or elevated 4N fraction > 6%) was identified in 9 (82%) of adenocarcinoma, 13 (72%) of high-grade dysplasia, 7 (15%) of low-grade dysplasia, and none (0%) of non-dysplastic mucosa. One-, 2-, and 7-year detection rates of high-grade dysplasia or adenocarcinoma in low-grade dysplasia patients with abnormal DNA content were 57%, 86%, and 88%, respectively, whereas low-grade dysplasia patients in the setting of normal DNA content had 1-, 2-, and 7-year detection rates of 10%, 10%, and 10%, respectively. The univariate and multivariate hazard ratios (HRs) for subsequent detection of high-grade dysplasia or adenocarcinoma in low-grade dysplasia patients with DNA content abnormality were 16.8 (p = <0.01) and 9.8 (p = <0.01), respectively. Among the 13 high-grade dysplasia patients with DNA content abnormality, 5 patients (38%) were subsequently found to have adenocarcinoma within a mean follow-up time of 3 months, whereas only 1 (20%) of the remaining 5 patients in the setting of normal DNA content developed adenocarcinoma in a month (HR = 2.6, p = 0.39). The overall 1- and 2-year detection rates of adenocarcinoma in all high-grade dysplasia patients (regardless of flow cytometric results) were 34% (95% confidence interval = 16-63%) and 47% (95% confidence interval = 23-79%), respectively. In conclusion, the majority of low-grade dysplasia patients (86%) in the setting of abnormal DNA content developed high-grade dysplasia or adenocarcinoma within 2 years and thus may benefit from resection, whereas those with normal DNA content may be followed with surveillance endoscopy. The presence of DNA content abnormality can also confirm a morphologic suspicion of high-grade dysplasia, which should be managed with resection, as nearly 50% of the high-grade dysplasia patients were found to have adenocarcinoma within 2 years.

Diagnosis and risk stratification of Barrett's dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue.

OBJECTIVE: The diagnosis of dysplasia in Barrett's oesophagus (BO) can be challenging, and reliable ancillary techniques are not available. This study examines if DNA content abnormality detected by flow cytometry can serve as a diagnostic marker of dysplasia and facilitate risk stratification of low-grade dysplasia (LGD) and indefinite for dysplasia (IND) patients using formalin-fixed paraffin-embedded (FFPE) BO samples with varying degrees of dysplasia. DESIGN: DNA flow cytometry was performed on 80 FFPE BO samples with high-grade dysplasia (HGD), 38 LGD, 21 IND and 14 negative for dysplasia (ND). Three to four 60-micron thick sections were cut from each tissue block, and the area of interest was manually dissected. RESULTS: DNA content abnormality was identified in 76 HGD (95%), 8 LGD (21.1%), 2 IND (9.5%) and 0 ND samples. As a diagnostic marker of HGD, the estimated sensitivity and specificity of DNA content abnormality were 95% and 85%, respectively. For patients with DNA content abnormality detected at baseline LGD or IND, the univariate HRs for subsequent detection of HGD or oesophageal adenocarcinoma (OAC) were 7.0 and 20.0, respectively (p =<0.001). CONCLUSIONS: This study demonstrates the promise of DNA flow cytometry using FFPE tissue in the diagnosis and risk stratification of dysplasia in BO. The presence of DNA content abnormality correlates with increasing levels of dysplasia, as 95% of HGD samples showed DNA content abnormality. DNA flow cytometry also identifies a subset of patients with LGD and IND who are at higher risk for subsequent detection of HGD or OAC.

Association of Aneuploidy and Flat Dysplasia With Development of High-Grade Dysplasia or Colorectal Cancer in Patients With Inflammatory Bowel Disease.

There is controversy over how to best manage patients with inflammatory bowel disease and flat low-grade dysplasia (fLGD) in the colon. We performed a retrospective analysis of formalin-fixed paraffin-embedded colon tissues with fLGD from 37 patients undergoing surveillance colonoscopy for inflammatory bowel disease from 1990 to 2015 at the University of California at San Francisco Medical Center, to determine whether detection of aneuploidy is associated with later development of high-grade dysplasia (HGD) or colorectal cancer. Medical data were collected from the patients for a mean follow-up time of 37 months. Using flow cytometry analysis of paraffin-embedded colon tissue, we detected aneuploidy in 15 of 37 samples with fLGD (40.5%). By comparison, aneuploidy was detected in 14 of 15 samples with flat HGD (93.3%) and 2 of 45 samples that were negative for dysplasia (4.4%). The univariate hazard ratio for subsequent detection of HGD or colorectal cancer in patients with fLGD and aneuploidy was 5.3 (95% CI, 1.542-24.121) within a mean follow-up time of 37 months. The presence of aneuploidy therefore identifies patients with fLGD in colon tissue who have an increased risk for HGD or colorectal cancer and may provide supportive evidence to a morphologic impression or suspicion of flat HGD.

Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification.

Mechanisms of initial cell fate decisions differ among species. To gain insights into lineage allocation in humans, we derived ten human embryonic stem cell lines (designated UCSFB1-10) from single blastomeres of four 8-cell embryos and one 12-cell embryo from a single couple. Compared with numerous conventional lines from blastocysts, they had unique gene expression and DNA methylation patterns that were, in part, indicative of trophoblast competence. At a transcriptional level, UCSFB lines from different embryos were often more closely related than those from the same embryo. As predicted by the transcriptomic data, immunolocalization of EOMES, T brachyury, GDF15 and active ß-catenin revealed differential expression among blastomeres of 8- to 10-cell human embryos. The UCSFB lines formed derivatives of the three germ layers and CDX2-positive progeny, from which we derived the first human trophoblast stem cell line. Our data suggest heterogeneity among early-stage blastomeres and that the UCSFB lines have unique properties, indicative of a more immature state than conventional lines.

Use of DNA flow cytometry in the diagnosis, risk stratification, and management of gastric epithelial dysplasia.

The natural history of gastric epithelial dysplasia and the consequential surveillance strategies are not well defined in the West. To date, the diagnosis relies on morphology, and no reliable adjunct methods, either immunohistochemical or molecular, have reproducibly been able to confirm the diagnosis and/or risk stratify gastric epithelial dysplasia. Yet, such a tool would be useful in confirming the diagnosis, and developing objective and rational surveillance guidelines. DNA flow cytometry was performed using formalin-fixed paraffin-embedded gastric tissue from 23 cases of high-grade dysplasia and 38 cases of low-grade dysplasia. Twenty-four benign background mucosal samples from the same cohort (20 biopsies and 4 surgical resections from 16 low- and 8 high-grade dysplasia cases) were utilized as controls. The presence of DNA content abnormality (aneuploidy or elevated 4N fraction) correlated with increasing levels of dysplasia, as DNA content abnormality was detected in 18 (78%) of 23 high-grade dysplasia, 5 (13%) of 38 low-grade dysplasia, and none of 24 non-dysplastic samples. 1 and 4-year detection rates of high-grade dysplasia or gastric adenocarcinoma in low-grade dysplasia patients with DNA content abnormality were 80% (p = 0.003) and 100% (p = 0.005), respectively, whereas patients with low-grade dysplasia but with normal DNA content had 1, 4, and 12-year detection rates of 23, 32, and 54%, respectively. The univariate hazard ratio (HR) for subsequent detection of high-grade dysplasia or gastric adenocarcinoma in low-grade dysplasia patients with DNA content abnormality was 6.9 (p = 0.001). Older patients (HR = 1.1, p = 0.005) and those with familial adenomatous polyposis (HR = 9.7, p = 0.029) also had an increased risk for developing high-grade dysplasia or gastric adenocarcinoma in the univariate analysis, but only DNA content abnormality demonstrated a significantly elevated HR of 5.9 in the multivariate analysis (p = 0.005). While older age showed a minimally elevated risk (HR = 1.1, p = 0.013), no other potential risk factors, including male gender, ethnicity, polypoid endoscopic appearance, Helicobacter pylori infection, and intestinal metaplasia, were significantly associated with subsequent detection of high-grade dysplasia or gastric adenocarcinoma in the multivariate analysis. Among the 18 high-grade dysplasia cases with DNA content abnormality, 13 cases (72%) developed gastric adenocarcinoma within a mean follow-up time of 9 months, conferring a HR of 2.5; however, this did not reach statistical significance. In conclusion, the presence of DNA content abnormality can identify a subset of low-grade dysplasia patients who are at increased risk for subsequent detection of high-grade dysplasia or gastric adenocarcinoma. It can also provide confirmatory evidence to a morphologic impression or suspicion of high-grade dysplasia. The majority of gastric epithelial dysplasia patients with DNA content abnormality developed high-grade dysplasia or gastric adenocarcinoma within a year and thus may benefit from more thorough and rigorous endoscopic surveillance.

DNA content analysis of colorectal serrated lesions detects an aneuploid subset of inflammatory bowel disease-associated serrated epithelial change and traditional serrated adenomas.

AIMS: Serrated lesions (SLs), including sessile serrated adenoma (SSA) and traditional serrated adenoma (TSA), are important premalignant lesions for colorectal cancer (CRC). Although a small subset of SLs are known to harbour TP53 mutations and Wnt/ß-catenin pathway activation, suggesting that they may develop dysplasia or CRC via a 'chromosomal instability (CIN)-like' pathway, it is unclear if aneuploidy (characteristic of conventional adenoma) ever develops in SLs and is associated with development of dysplasia or CRC, in this context. METHODS AND RESULTS: DNA flow cytometry was performed on 31 inflammatory bowel disease (IBD)-associated SLs without dysplasia [including 10 non-targeted 'serrated epithelial change' (SEC), 14 SSAs and seven hyperplastic polyps (HPs)] as well as 48 dysplastic SSAs and TSAs. One (10%) of 10 SEC cases demonstrated aneuploidy and subsequently developed high-grade dysplasia (HGD) within 4 months, whereas the remaining SEC cases showed normal DNA content without evidence of dysplasia or CRC on follow-up. One (3.3%) of 30 TSAs without HGD and two (66.7%) of three TSAs with HGD also showed aneuploidy, but no patient developed CRC. By contrast, all SSAs (with or without dysplasia) and HPs showed normal DNA content, but four SSA cases still developed dysplasia or CRC on follow-up. CONCLUSIONS: Unlike SSAs and HPs, a small subset of SEC and TSA cases demonstrated aneuploidy, suggesting that they can develop neoplasia via the CIN pathway. DNA content analysis of a larger number of SEC cases, with adequate follow-up, may allow for a more precise determination of aneuploidy incidence and neoplasia risk.

Diffusion-weighted imaging of hyperpolarized [13 C]urea in mouse liver.

PURPOSE: To compare the apparent diffusion coefficient (ADC) of hyperpolarized (HP) [13 C,15 N]urea to the ADC of endogenous water in healthy and fibrotic mouse liver. MATERIALS AND METHODS: ADC measurements for water and [13 C]urea were made in agarose phantoms at 14.1T. Next, the ADC of water and injected HP [13 C,15 N]urea were measured in eight CD1 mouse livers before and after induction of liver fibrosis using CCl4 . Liver fibrosis was quantified pathologically using the modified Brunt fibrosis score and compared to the measured ADC of water and urea. RESULTS: In cell-free phantoms with 12.5% agarose, water ADC was nearly twice the ADC of urea (1.93 × 10-3 mm2 /s vs. 1.00 × 10-3 mm2 /s). The mean ADC values of water and [13 C,15 N]urea in healthy mouse liver (±SD) were nearly identical [(0.75 ± 0.11) × 10-3 mm2 /s and (0.75 ± 0.22) × 10-3 mm2 /s, respectively]. Mean water and [13 C,15 N]urea ADC values in fibrotic liver (±SD) were (0.84 ± 0.22) × 10-3 mm2 /s and (0.75 ± 0.15) × 10-3 mm2 /s, respectively. Neither water nor urea ADCs were statistically different in the fibrotic livers compared to baseline (P = 0.14 and P = 0.99, respectively). Water and urea ADCs were positively correlated at baseline (R2 = 0.52 and P = 0.045) but not in fibrotic livers (R2 = 0.23 and P = 0.23). CONCLUSION: ADC of injected hyperpolarized urea in healthy liver reflects a smaller change as compared to free solution than ADC of water. This may reflect differences in cellular compartmentalization of the two compounds. No significant change in ADC of either water or urea were observed in relatively mild stages of liver fibrosis. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:141-151.

Heightened Immune Activation in Fetuses with Gastroschisis May Be Blocked by Targeting IL-5.

The development of the fetal immune system during pregnancy is a well-orchestrated process with important consequences for fetal and neonatal health, but prenatal factors that affect immune activation are poorly understood. We hypothesized that chronic fetal inflammation may lead to alterations in development of the fetal immune system. To test this hypothesis, we examined neonates with gastroschisis, a congenital abdominal wall defect that leads to exposure of the fetal intestines to amniotic fluid, with resultant intestinal inflammation. We determined that patients with gastroschisis show high systemic levels of inflammatory cytokines and chemokines such as eotaxin, as well as earlier activation of CD4(+) and CD8(+) effector and memory T cells in the cord blood compared with controls. Additionally, increased numbers of T cells and eosinophils infiltrate the serosa and mucosa of the inflamed intestines. Using a mouse model of gastroschisis, we observed higher numbers of eosinophils and both type 2 and type 3 innate lymphoid cells (ILC2 and ILC3), specifically in the portion of organs exposed to the amniotic fluid. Given the role of IL-5 produced by ILC2 in regulating eosinophil development and survival, we determined that maternal or fetal administration of the anti-IL-5 neutralizing Ab, or a depleting Ab against ILCs, can both effectively reduce intestinal eosinophilia. Thus, a congenital anomaly causing chronic inflammation can alter the composition of circulating and tissue-resident fetal immune cells. Given the high rate of prenatal and neonatal complications in these patients, such changes have clinical significance and might become targets for fetal therapy.