Characterization of the ultrastructure in the uterovaginal junction of the hen

In poultry, the infundibulum is the place of fertilization, eggshell production, and sperm storage, while its uterovaginal junction (UVJ) is regarded as the most important site, which has abundant sperm storage tubules (SST). We examined the ultrastructure of the epithelium with relation to its unique secretory cytology in the UVJ of hens using transmission electron microscopy. The epithelium of the UVJ is lined with ciliated and secretory cells. Ciliated cells are characterized with light and dense secretory granules in supernuclear cytoplasm. Dense secretory granules in ciliated cells are larger in diameter (one μm), surrounded with a transparent rim and concentric layers, whereas the dense granules in the ciliated cells of SST are smaller (0.52 μm) in size and not surrounded by any transparent rim or layer. Ciliated cells also are involved in the shedding of exosomes and secretory vesicles in the lumen. Secretory exosomes are in close contact with cilia and directly release from the apical border into the lumen. Cell junctions are widely distributed between these cells. The secretory cells are associated with the release of secretions via apocrine blebs from microvilli and secretory vesicles, which protrude out from the surface of the epithelium. The dense secretory granules in these cells are smaller in size (0.6 μm), absent of a transparent rim or layers, and are released into the lumen through secretory vesicles. The intracellular multivesicular body (MVB) also is observed in the supernuclear cytoplasm of secretory cells, which are related to the production of exosomes. In general, the apical protrusion of the epithelium in the form of apocrine secretions, the releasing of exosomes, the identification of intracellular MVB, and the release of dense granules give the epithelium a distinct morphology in the UVJ of the hen oviduct.

Abstract PD7-01: Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer

Background: Emerging evidence demonstrates the effectiveness of targeted gene sequencing panels as a practical method for the diagnosis of inherited susceptibility to breast cancer. Sequencing of multiple high and moderate risk genes simultaneously accelerates the discovery of deleterious mutations (DM) or variants of unknown significance (VUS). However, a consequence of Multiplex Gene Panel (MGP) testing is the discovery of unexpected DMs in high or moderate risk genes other than BRCA1 or BRCA2 (BRCA1/2). The overall clinical utility and incremental gain of information conferred by MGP testing in hereditary cancer risk assessment is still unknown.

Methods: We are conducting a multicenter prospective cohort study of patients undergoing cancer-risk assessment using a 25 gene sequencing panel, which includes APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Patients were recruited from August 2014 to June 2015 at three medical centers. Patients are enrolled if they meet standard criteria for genetic testing or are predicted to have a ≥ 2.5% probability of inherited susceptibility to cancer calculated by validated risk prediction models. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: HCP testing was performed for 332 patients referred for clinical suspicion of hereditary breast and ovarian cancer (HBOC). In this cohort, 96.7% were female (n=321) and the mean age was 50 years (standard deviation, SD=12.2); race/ethnicity was 43.1% Hispanic (n=143), 37% Non-Hispanic White (n=123), 4.2% Black (n=14), 10.5% Asian (n=35), and 1.8% other (n=6). Among this cohort, 37 tested positive for one deleterious mutation (DM) (11.1%: 95% confidence interval (CI), 8.2% to 15%) and 118 patients carried at least one variant of uncertain significance (VUS) (35.5%: 95% CI, 30.6% to 69%). Excluding BRCA1 or BRCA2, 14 patients (4.3%: 95% CI, 2.6% to 7.2%) have a DM in ATM (n=3), CHEK2 (n=2), MSH6 (n=1), MUTYH (n=3), PALB2 (n=1), PMS2 (n=1), RAD51C (n=2), and TP53 (n=2). In a patient with an unexpected PMS2 mutation, enhanced cancer surveillance based on Lynch Syndrome guidelines was recommended. Among 160 patients with a history of invasive breast cancer or breast DCIS, 19 patients carried a DM (11.8 %: 95 CI, 7.7% to 17.8%).

Conclusion: In this multicenter prospective cohort study among a diverse group of participants undergoing 25-gene MGP testing, 11.1% of participants tested positive for a DM. Among participants testing negative for BRCA1 and BRCA2, MGP testing identified DMs in 4.3% of participants prompting clinically appropriate risk reduction recommendations and enhanced cancer surveillance. Ongoing recruitment and long-term follow-up are in progress.

Citation Format: Idos GE, Kurian AW, Mcdonnell KJ, Ricker CN, Sturgeon DY, Culver JO, Lowstuter K, Hartman A-R, Allen B, Teeter C-R, Kingham KE, Koff R, Lebensohn A, Chun NM, Mills MA, Petrovchich I, Hong C, Ladabaum U, Ford JM, Gruber SB. Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD7-01.

Abstract P2-09-07: The patient experience in a prospective trial of multiplex gene panel testing for cancer risk

Background: Multiplex gene sequencing panels (MGP) are increasingly used for assessment of hereditary breast cancer risk. Compared to testing for BRCA1 and BRCA2 (BRCA1/2) only, testing more genes increases the likelihood of identifying a deleterious mutation (DM) and/or a variant of uncertain significance (VUS), which might cause distress, uncertainty or regret about testing. Little is known about the patient experience of MGP testing.

Methods: We conducted a prospective study of MGP testing, using a panel of 25 genes: APC, ATM, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD51C, RAD51D, SMAD4, STK11, and TP53. Participants were enrolled at three medical centers and were eligible if they met standard genetic testing guidelines or if they had a ≥2.5% probability of a DM in any gene on the panel, as calculated by predictive models (e.g. IBIS, Penn II, MMRPro). Participants were surveyed about their experiences with MGP testing including distress and uncertainty at baseline (before test results disclosure) and three months later. The 25-item Multidimensional Impact of Cancer Risk Assessment (MICRA) scale measured distress, uncertainty and positive experiences at three months after testing. We present a planned interim analysis after enrolling 500 of 2000 total participants.

Results: Of 500 participants, 332 (66%) were referred for suspicion of hereditary breast/ovarian cancer syndrome. Of these 332, 97% were female, 79% were white, 43% were Hispanic and 33% were Spanish-speaking only; for 25%, high school was their highest level of education. A total of 48% had breast cancer, 5% had ovarian cancer, and 7% had another cancer: 11% had a DM and 35% had VUS in one or more genes. At study entry most participants thought about cancer rarely or not at all (69%, 95% confidence interval (CI) 58%-77%), and few (7%, CI 3%-14%) had thoughts of cancer that affected their daily lives; results were unchanged three months later, after genetic results disclosure (Chi-squared test, p-value >0.1). MICRA scores at three months were low for distress (mean score 2 out of a possible 30) and uncertainty (mean score 7 out of 45), and high for positive testing experiences (mean score 9 out of 15). Most (82%, CI 72%-88%) participants wanted to know all of their MGP results even if the clinical relevance was not fully understood, and most (87%, CI 79%-93%) never regretted learning their MGP results.

Conclusions: Among diverse participants of a prospective, multi-center MGP testing trial, cancer- and genetic testing-related distress were low at entry and remained low three months later. These results provide no evidence for an increase in distress or uncertainty after MGP. Longer-term follow-up in a larger cohort is underway.

Citation Format: Kurian AW, Idos G, McDonnell K, Ricker C, Sturgeon D, Culver J, Lowstuter K, Hartman A-R, Allen B, Rowe-Teeter C, Kingham KE, Koff RB, Lebensohn A, Chun NM, Petrovchich IM, Mills MA, Hong C, Ladabaum U, Ford JM, Gruber SB. The patient experience in a prospective trial of multiplex gene panel testing for cancer risk. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-07.

Thermoneutral Housing Accelerates Metabolic Inflammation to Potentiate Atherosclerosis but Not Insulin Resistance

Chronic, low-grade inflammation triggered by excess intake of dietary lipids has been proposed to contribute to the pathogenesis of metabolic disorders, such as obesity, insulin resistance, type 2 diabetes, and atherosclerosis. Although considerable evidence supports a causal association between inflammation and metabolic diseases, most tests of this link have been performed in cold-stressed mice that are housed below their thermoneutral zone. We report here that thermoneutral housing of mice has a profound effect on the development of metabolic inflammation, insulin resistance, and atherosclerosis. Mice housed at thermoneutrality develop metabolic inflammation in adipose tissue and in the vasculature at an accelerated rate. Unexpectedly, this increased inflammatory response contributes to the progression of atherosclerosis but not insulin resistance. These findings not only suggest that metabolic inflammation can be uncoupled from obesity-associated insulin resistance, but also point to how thermal stress might limit our ability to faithfully model human diseases in mice.

Challenges in the Management of Breast Cancer in a Low Resource Setting in South East Asia

BACKGROUND

Breast cancer is the second most common cancer in women in Cambodia, a low income country in SouthEast Asia. The Sihanouk Hospital Centre of Hope (SHCH) is a charity hospital set up by an international nongovernmental organisation, HOPE Worldwide. In 2008, SHCH partnered with AmeriCares, a global health organisation to set up and deliver a breast cancer programme to provide education, diagnosis and treatment for women with breast cancer. The objective of this study is to characterise the presentation, diagnosis, treatment and outcomes of women treated under this program.

MATERIALS AND METHODS

A total of 215 women newly diagnosed with breast cancer from 1 March 2008 until 31 March 2011 were studied. Age at diagnosis, tumour size, histological type, tumour grade, ER, lymph node involvement, treatment modalities (surgery, radiotherapy, chemotherapy, hormone therapy) were recorded. Data on mortality at 3 years were obtained whenever possible.

RESULTS

The median age was 47 years old. Some 77.8% were diagnosed with stage 3 and 4 lesions, and 78.5% underwent mastectomy, of which 28.4% the intent was palliative. Of those whose ER status were known, only 48.3% were ER positive. Only 6 patients could afford chemotherapy while only 1 patient had radiotherapy. Hormone therapy was provided free for those who were ER positive. The overall survival rate at 3 years was 39.1%.

CONCLUSIONS

Breast cancer presents at a late stage, and because treatment is suboptimal, survival is poor in Cambodia. A more aggressive approach to early detection and treatment needs to be developed to improve outcome from this potentially curable disease.

Palmoplantar Keratoderma in Slurp2-Deficient Mice

SLURP1, a member of the Ly6 protein family, is secreted by suprabasal keratinocytes. Mutations in SLURP1 cause a palmoplantar keratoderma (PPK) known as mal de Meleda. Another secreted Ly6 protein, SLURP2, is encoded by a gene located ~20 kb downstream from SLURP1. SLURP2 is produced by suprabasal keratinocytes. To investigate the importance of SLURP2, we first examined Slurp2 knockout mice in which exon 2–3 sequences had been replaced with lacZ and neo cassettes. Slurp2^−/− mice exhibited hyperkeratosis on the volar surface of the paws (i.e., PPK), increased keratinocyte proliferation, and an accumulation of lipid droplets in the stratum corneum. They also exhibited reduced body weight and hind limb clasping. These phenotypes are very similar to those of Slurp1^−/− mice. To solidify a link between Slurp2 deficiency and PPK and to be confident that the disease phenotypes in Slurp2^−/− mice were not secondary to the effects of the lacZ and neo cassettes on Slurp1 expression, we created a new line of Slurp2 knockout mice (Slurp2X^−/−) in which Slurp2 was inactivated with a simple nonsense mutation. Slurp2X^−/− mice exhibited the same disease phenotypes. Thus, Slurp2 deficiency and Slurp1 deficiencies cause the same disease phenotypes.

Endothelial NOTCH1 is suppressed by circulating lipids and antagonizes inflammation during atherosclerosis

Briot et al. show that inflammatory lipids deriving from a high-fat diet suppress NOTCH1 expression and signaling in adult arterial endothelium and propose that reduction of endothelial NOTCH1 is a predisposing factor in the onset of atherosclerosis.

Although much progress has been made in identifying the mechanisms that trigger endothelial activation and inflammatory cell recruitment during atherosclerosis, less is known about the intrinsic pathways that counteract these events. Here we identified NOTCH1 as an antagonist of endothelial cell (EC) activation. NOTCH1 was constitutively expressed by adult arterial endothelium, but levels were significantly reduced by high-fat diet. Furthermore, treatment of human aortic ECs (HAECs) with inflammatory lipids (oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine [Ox-PAPC]) and proinflammatory cytokines (TNF and IL1β) decreased Notch1 expression and signaling in vitro through a mechanism that requires STAT3 activation. Reduction of NOTCH1 in HAECs by siRNA, in the absence of inflammatory lipids or cytokines, increased inflammatory molecules and binding of monocytes. Conversely, some of the effects mediated by Ox-PAPC were reversed by increased NOTCH1 signaling, suggesting a link between lipid-mediated inflammation and Notch1. Interestingly, reduction of NOTCH1 by Ox-PAPC in HAECs was associated with a genetic variant previously correlated to high-density lipoprotein in a human genome-wide association study. Finally, endothelial Notch1 heterozygous mice showed higher diet-induced atherosclerosis. Based on these findings, we propose that reduction of endothelial NOTCH1 is a predisposing factor in the onset of vascular inflammation and initiation of atherosclerosis.

LXRs link metabolism to inflammation through Abca1-dependent regulation of membrane composition and TLR signaling

The liver X receptors (LXRs) are transcriptional regulators of lipid homeostasis that also have potent anti-inflammatory effects. The molecular basis for their anti-inflammatory effects is incompletely understood, but has been proposed to involve the indirect tethering of LXRs to inflammatory gene promoters. Here we demonstrate that the ability of LXRs to repress inflammatory gene expression in cells and mice derives primarily from their ability to regulate lipid metabolism through transcriptional activation and can occur in the absence of SUMOylation. Moreover, we identify the putative lipid transporter Abca1 as a critical mediator of LXR's anti-inflammatory effects. Activation of LXR inhibits signaling from TLRs 2, 4 and 9 to their downstream NF-κB and MAPK effectors through Abca1-dependent changes in membrane lipid organization that disrupt the recruitment of MyD88 and TRAF6. These data suggest that a common mechanism-direct transcriptional activation-underlies the dual biological functions of LXRs in metabolism and inflammation.

Short communication: Evaluation of amino acid consumption and necessary profiles of Streptococcus thermophilus T1C2 in controlled pH batch fermentations

The objective of the present study was to elucidate the relationship between amino acid consumption and necessary profiles of Streptococcus thermophilus T1C2 to guide the design of media for high-cell-density culture. The amino acid consumption and necessary patterns of S. thermophilus T1C2 were investigated in the complete chemically defined medium. For amino acid consumption profiles throughout the growth of S. thermophilus T1C2, the most abundantly consumed amino acids were Gln and Arg, which accounted for 19 and 20% of total amino acids consumed, respectively. Asparagine, Thr, Ser, Ala, Val, Met, Leu, and Lys, consumptions of which ranged from 3 to 10% of total amino acids consumed, were the second most intensively consumed amino acids. For necessary amino acid patterns, the amount of Cys, which counted for 11% of total amino acids needed, was significantly higher than the amounts required for other amino acids in growth of S. thermophilus T1C2. The necessary amounts of Asp, Asn, Glu, Gln, Arg, Ala, Met, and Tyr ranked second, ranging from 5 to 8% of total amino acids needed. Compared with necessary amounts, the consumption of Asn, Thr, Ser, Gln, Arg, Ala, Val, Leu, Lys, His, and Phe exceeded the necessary amounts for growth of S. thermophilus T1C2 remarkably. Consumption of Gly, Met, Ile, Trp, and Pro was slightly higher than the necessary amounts. Consumption of Asp, Glu, Tyr, and Cys was lower than the necessary amounts. The overall consumption of amino acids exceeded the required amount for growth of S. thermophilus T1C2 almost 2.43 times, which implied a significant nitrogen wasting.

Calreticulin promotes angiogenesis via activating nitric oxide signalling pathway in rheumatoid arthritis

Calreticulin (CRT) is a multi-functional endoplasmic reticulum protein implicated in the pathogenesis of rheumatoid arthritis (RA). The present study was undertaken to determine whether CRT was involved in angiogenesis via the activating nitric oxide (NO) signalling pathway. We explored the profile of CRT expression in RA (including serum, synovial fluid and synovial tissue). In order to investigate the role of CRT on angiogenesis, human umbilical vein endothelial cells (HUVECs) were isolated and cultured in this study for in-vitro experiments. Our results showed a significantly higher concentration of CRT in serum (5·4 ± 2·2 ng/ml) of RA patients compared to that of osteoarthritis (OA, 3·6 ± 0·9 ng/ml, P < 0·05) and healthy controls (HC, 3·7 ± 0·6 ng/ml, P < 0·05); and significantly higher CRT in synovial fluid (5·8 ± 1·2 ng/ml) of RA versus OA (3·7 ± 0·3 ng/ml, P < 0·05). High levels of CRT are expressed in synovial membrane localized predominantly to inflammatory cells and synovial perivascular areas in both the lining and sublining layers of RA synovial tissue (RAST). Increased nitric oxide (NO) production and phosphorylation level of endothelial nitric oxide synthase (eNOS) were measured in HUVECs following CRT stimulation, while the total eNOS expression was not significantly changed. Furthermore, CRT promoted the proliferation, migration and tube formation of HUVECs, which were significantly inhibited by a specific eNOS inhibitor. These findings suggested that CRT may be involved in angiogenesis events in RA through NO signalling pathways, which may provide a potential therapeutic target in the treatment of RA.

The LXR-Idol axis differentially regulates plasma LDL levels in primates and mice

The LXR-regulated E3 ubiquitin ligase IDOL controls LDLR receptor stability independent of SREBP and PCSK9, but its relevance to plasma lipid levels is unknown. Here we demonstrate that the effects of the LXR-IDOL axis are both tissue and species specific. In mice, LXR agonist induces Idol transcript levels in peripheral tissues but not in liver, and does not change plasma LDL levels. Accordingly, Idol-deficient mice exhibit elevated LDLR protein levels in peripheral tissues, but not in the liver. By contrast, LXR activation in cynomolgus monkeys induces hepatic IDOL expression, reduces LDLR protein levels, and raises plasma LDL levels. Knockdown of IDOL in monkeys with an antisense oligonucleotide blunts the effect of LXR agonist on LDL levels. These results implicate IDOL as a modulator of plasma lipid levels in primates and support further investigation into IDOL inhibition as a potential strategy for LDL lowering in humans.

Dietary cholesterol promotes adipocyte hypertrophy and adipose tissue inflammation in visceral, but not in subcutaneous, fat in monkeys

OBJECTIVE

Excessive caloric intake is associated with obesity and adipose tissue dysfunction. However, the role of dietary cholesterol in this process is unknown. The aim of this study was to determine whether increasing dietary cholesterol intake alters adipose tissue cholesterol content, adipocyte size, and endocrine function in nonhuman primates.

APPROACH AND RESULTS

Age-matched, male African Green monkeys (n=5 per group) were assigned to 1 of 3 diets containing 0.002 (low [Lo]), 0.2 (medium [Med]), or 0.4 (high [Hi]) mg cholesterol/kcal. After 10 weeks of diet feeding, animals were euthanized for adipose tissue, liver, and plasma collection. With increasing dietary cholesterol, free cholesterol (FC) content and adipocyte size increased in a stepwise manner in visceral, but not in subcutaneous fat, with a significant association between visceral adipocyte size and FC content (r(2)=0.298; n=15; P=0.035). In visceral fat, dietary cholesterol intake was associated with (1) increased proinflammatory gene expression and macrophage recruitment, (2) decreased expression of genes involved in cholesterol biosynthesis and lipoprotein uptake, and (3) increased expression of proteins involved in FC efflux.

CONCLUSIONS

Increasing dietary cholesterol selectively increases visceral fat adipocyte size, FC and macrophage content, and proinflammatory gene expression in nonhuman primates. Visceral fat cells seem to compensate for increased dietary cholesterol by limiting cholesterol uptake/synthesis and increasing FC efflux pathways.

Transgenic expression of dominant-active IDOL in liver causes diet-induced hypercholesterolemia and atherosclerosis in mice

RATIONALE

The E3 ubiquitin ligase inducible degrader of the low-density lipoprotein receptor (IDOL) triggers lysosomal degradation of the low-density lipoprotein receptor. The tissue-specific effects of the IDOL pathway on plasma cholesterol and atherosclerosis have not been examined.

OBJECTIVE

Given that the liver is the primary determinant of plasma cholesterol levels, we sought to examine the consequence of effect of chronic liver-specific expression of a dominant-active form of IDOL in mice.

METHODS AND RESULTS

We expressed a degradation-resistant, dominant-active form of IDOL (super IDOL [sIDOL]) in C57Bl/6J mice from the liver-specific albumin promoter (L-sIDOL transgenics). L-sIDOL mice were fed a Western diet for 20 or 30 weeks and then analyzed for plasma lipid levels and atherosclerotic lesion formation. L-sIDOL mice showed dramatic reductions in hepatic low-density lipoprotein receptor protein and increased plasma low-density lipoprotein cholesterol levels on both chow and Western diets. Moreover, L-sIDOL mice developed marked atherosclerotic lesions when fed a Western diet. Lesion formation in L-sIDOL mice was more robust than in apolipoprotein E*3 Leiden mice and did not require the addition of cholate to the diet. Western diet-fed L-sIDOL mice had elevated expression of liver X receptor target genes and proinflammatory genes in their aortas.

CONCLUSIONS

Liver-specific expression of dominant-active IDOL is associated with hypercholesterolemia and a marked elevation in atherosclerotic lesions. Our results show that increased activity of the IDOL pathway in the liver can override other low-density lipoprotein receptor regulatory pathways leading to cardiovascular disease. L-sIDOL mice are a robust, dominantly inherited, diet-inducible model for the study of atherosclerosis.