Man Ho Choi

Sitosterolemia Presenting With Severe Hypercholesterolemia and Intertriginous Xanthomas in a Breastfed Infant: Case Report and Brief Review

CONTEXT Sitosterolemia is an autosomal recessive disorder characterized by increased intestinal absorption of plant sterols. It is caused by mutations in genes encoding ATP-binding cassette, subfamily G5 (ABCG5) or G8 (ABCG8), and clinical features include elevated plant sterol levels, xanthomas, and accelerated atherosclerosis. Although it was originally reported in patients with normolipemic xanthomas, patients with sitosterolemia also hyperabsorb cholesterol, and serum cholesterol levels tend to be elevated. OBJECTIVE We report an infant with sitosterolemia who presented with severe hypercholesterolemia and intertriginous xanthomas. CASE REPORT A 15-month-old Korean girl presented with yellow dermal plaques over flexural areas including the wrist, neck, and gluteal folds, which were consistent with intertriginous xanthomas. The lesions were first noticed at 3 months of age when she was being exclusively breastfed. Her total cholesterol and low-density lipoprotein-cholesterol levels were 675 and 540 mg/dL, respectively. A low-fat/low-cholesterol diet and cholestyramine therapy were introduced. Unexpectedly, her serum cholesterol level decreased dramatically and normalized in 2 months. Cholestyramine was tapered off. The xanthomas also regressed and disappeared by 3 years of age. Gas chromatography-mass spectrometric analysis was performed with serum drawn at 3 years of age when her low-density lipoprotein-cholesterol was 118 mg/dL, which revealed striking elevation of her sitosterol level at 19.36 mg/dL. Direct sequencing for ABCG5 revealed compound heterozygous null mutations c.904+1G>A (p.Met302Asnfs*82) and c.1336C>T(p.Arg446*). CONCLUSIONS Our case suggests that sitosterolemia can present with severe hypercholesterolemia and intertriginous xanthomas. Sitosterolemia should be suspected when a patient with hypercholesterolemia shows unexpectedly good response to dietary modification or bile acid sequestrant therapy.

Characteristic features of ageing in Korean women's hair and scalp.

Background  The effect of age on hair properties has previously been investigated in white and Japanese women; however, little is known of the age‐related characteristic features of hair in Korean women.

Improved detectability of sex steroids from frozen sections of breast cancer tissue using GC-triple quadrupole-MS

Sex steroids in clinical endocrinology have been mainly investigated with peripheral blood and urine samples, while there is limited information regarding the local levels within tissues. To improve analytical properties of sex steroids from trace amounts of tissue samples, two-phase extractive ethoxycarbonlyation and subsequent pentafluoropropionyl derivatization coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. The optimized analytical conditions led to excellent chromatographic separation of 15 estrogens, 6 androgens, and 2 progestins. The quantitative results were calculated based on in-house control samples as the steroid-free tissues, and the precision and accuracy were 4.2%-26.8% and 90.8%-116.4%, respectively. The on-column limit of quantification was from 180 fg to 0.5 pg for androgens and estrogens, and 1.25 pg for progestins, which were found to be linear (r2 > 0.990). The validated method was then applied to quantify 7 sex steroids from three 100-μm-thick frozen breast tissue slices from postmenopausal patients with breast cancer. This is the first report on the improved GC-MS/MS method for the detection of androgens and pregnenolone from breast cancer tissues, and it can be a useful technique to measure the local levels of sex steroids, thus, enhancing our understanding of the pathophysiological significances of steroidogenesis.

Differential lactate and cholesterol synthetic activities in XY and XX Sertoli cells

SRY, a sex-determining gene, induces testis development in chromosomally female (XX) individuals. However, mouse XX Sertoli cells carrying Sry (XX/Sry Sertoli cells) are incapable of fully supporting germ cell development, even when the karyotype of the germ cells is XY. While it has therefore been assumed that XX/Sry Sertoli cells are not functionally equivalent to XY Sertoli cells, it has remained unclear which specific functions are affected. To elucidate the functional difference, we compared the gene expression of XY and XX/Sry Sertoli cells. Lactate and cholesterol metabolisms, essential for nursing the developing germ cells, were down-regulated in XX/Sry cells, which appears to be caused at least in part by the differential expression of histone modification enzymes SMCX/SMCY (H3K4me3 demethylase) and UTX/UTY (H3K27me3 demethylase) encoded by the sex chromosomes. We suggest that down-regulation of lactate and cholesterol metabolism that may be due to altered epigenetic modification affects the nursing functions of XX/Sry Sertoli cells.

Effects of cytokines derived from cancer-associated fibroblasts on androgen synthetic enzymes in estrogen receptor-negative breast carcinoma

PurposeThe tumor microenvironment plays pivotal roles in promotion of many malignancies. Cancer-associated fibroblasts (CAFs) have been well-known to promote proliferation, angiogenesis, and metastasis but mechanistic understanding of tumor–stroma interactions is not yet complete. Recently, estrogen synthetic enzymes were reported to be upregulated by co-culture with stromal cells in ER positive breast carcinoma (BC) but effects of co-culture on androgen metabolism have not been extensively examined. Therefore, we evaluated roles of CAFs on androgen metabolism in ER-negative AR-positive BC through co-culture with CAFs.MethodsConcentrations of steroid hormone in supernatant of co-culture of MDA-MB-453 and primary CAFs were measured using GC–MS. Cytokines derived from CAFs were determined using Cytokine Array. Expressions of androgen synthetic enzymes were confirmed using RT-PCR and Western blotting. Correlations between CAFs and androgen synthetic enzymes were analyzed using triple-negative BC (TNBC) patient tissues by immunohistochemistry.ResultsCAFs were demonstrated to increase expressions and activities of 17βHSD2, 17βHSD5, and 5α-Reductase1. IL-6 and HGF that were selected as potential paracrine mediators using cytokine array induced 17βHSD2, 17βHSD5, and 5α-Reductase1 expression. Underlying mechanisms of IL-6 paracrine regulation of 17βHSD2 and 17βHSD5 could be partially dependent on phosphorylated STAT3, while phosphorylated ERK could be involved in HGF-mediated 5α-Reductase1 induction. α-SMA status was also demonstrated to be significantly correlated with 17βHSD2 and 17βHSD5 status in TNBC tissues, especially AR-positive cases.ConclusionsResults of our present study suggest that both IL-6 and HGF derived from CAFs could contribute to the intratumoral androgen metabolism in ER-negative BC patients.

Ad4BP/SF-1 regulates cholesterol synthesis to boost the production of steroids

Housekeeping metabolic pathways such as glycolysis are active in all cell types. In addition, many types of cells are equipped with cell-specific metabolic pathways. To properly perform their functions, housekeeping and cell-specific metabolic pathways must function cooperatively. However, the regulatory mechanisms that couple metabolic pathways remain largely unknown. Recently, we showed that the steroidogenic cell-specific nuclear receptor Ad4BP/SF-1, which regulates steroidogenic genes, also regulates housekeeping glycolytic genes. Here, we identify cholesterogenic genes as the targets of Ad4BP/SF-1. Further, we reveal that Ad4BP/SF-1 regulates Hummr, a candidate mediator of cholesterol transport from endoplasmic reticula to mitochondria. Given that cholesterol is the starting material for steroidogenesis and is synthesized from acetyl-CoA, which partly originates from glucose, our results suggest that multiple biological processes involved in synthesizing steroid hormones are governed by Ad4BP/SF-1. To our knowledge, this study provides the first example where housekeeping and cell-specific metabolism are coordinated at the transcriptional level.Takashi Baba and colleagues show that the steroidogenic cell-specific nuclear receptor Ad4BP/SF-1 targets cholesterogenic genes. Given that cholesterol is a precursor of the steroid hormones, this study suggests that Ad4BP/SF-1 regulates the synthesis of cholesterol to boost the production of steroids.

Supported liquid extraction coupled to gas chromatography-selective mass spectrometric scan modes for serum steroid profiling

Although, steroid profiling is being applied in clinical and biochemical studies, improvement of the technique is still needed for accurate quantification of steroids in case of limited biological sample volumes. To improve analytical sensitivity and selectivity in comparison to that of conventional methods, a method that comprises supported liquid extraction (SLE) and gas chromatography-mass spectrometry with a combination of selected-reaction and selected-ion monitoring modes (GC-SRM/SIM-MS) was developed. Here, this combination of SLE purification with GC-MS method was optimized with 37 different types of steroids and the results were compared to a solid-phase extraction (SPE) method. The devised assay led to an increase in extraction efficiency with the good chromatographic selectivity through a single extraction step. The limits of quantification of the serum steroids, ranged from 0.2 to 5 ng mL-1, except for cholesterol (0.2 μg mL-1), and the correlation coefficients for calibration curves were higher than 0.99. The precision and accuracy were 1.4%-10.5% and 82.7%-115.3%, respectively. The overall recoveries of 30 steroids ranged from 62.1% to 104.3%, while that of 7 sterols was 44.7%-75.7%. Then, this validated method was applied to monitor the serum steroid levels of mice, which showed significant sex and age dependent metabolic patterns. This technique can be used to evaluate the metabolic changes occurring in animal models as well as in clinical patients.

Mass spectrometry-based metabolic signatures of sex steroids in breast cancer

Owing to controversy over the effects of steroids on breast cancer pathophysiology, comprehensive quantification of steroid hormones has been extensively considered in both clinical practice and biomarker discovery studies. In contrast to the traditional immunoaffinity-based assays, which show cross-reactivity and have poor validity at low levels of sex steroids, mass spectrometry is becoming a promising tool for measuring steroid levels in complex biological specimens. The Endocrine Society has announced and continuously updated on technical advances to apply high-quality breakthroughs in the clinical sciences. To avoid incorrect estimation of the steroids of interest, however, further emphasis should be made on the efficient separation by chromatography, such as gas and liquid chromatography, prior to mass spectrometric (MS) detection. Recent advances in MS-based analysis of sex steroids associated with breast cancer enable accurate quantification of circulating as well as localized steroids from frozen tissue slices, allowing these assays to be more powerful in clinical practice.

PS 11-24 IMPACT OF BLOOD PRESSURE LEVEL ON ACETYLCOHOLINE INDUCED CORONARY ARTERY SPASM

Objective: Although autonomic nervous system activity may play an important role in coronary artery spasm (CAS), few studies have been published on the relationships between CAS and blood pressure (BP) level. This study was aimed to investigate the relationship between CAS and BP levels. Design and Method: A total of 5,304 consecutive patients with resting chest pain and without significant stenosis who underwent ACH provocation testing were enrolled.1193 patients were excluded owing to miscellaneous reasons and finally, 4,102 patients were included. Patients were categorized by BP levels. Significant CAS was defined as ≥ 70% narrowing by ACH provocation. To adjust potential confounders, a propensity score matched (PSM) analysis was performed using the logistic regression model. Results: After PSM analysis, frequency of CAS was analyzed according to BP level. (5 models; <115 mmHg vs 115–124 (model 1), 125–134 (model 2), 135–144 (model 3), 145–155 (model 4), ≥155 mmHg (model 5), respectively). In overall patients, frequency of CAS was significantly lower in model 4 and 5 [model 4–379 pairs, C-statistic = 0.723, CAS case 186 (49%), PSM RR 0.74 (CI 0.55–0.98), p = 0.042; model 5–385 pairs, C-statistic = 0.746, CAS case 200 (51.9%), PSM RR 0.70 (CI 0.52–0.93), p = 0.017]. In normotensives, frequency of CAS was significantly lower in in model 5 (150 pairs, C-statistic = 0.772, CAS case 82 (54.6%), PSM RR 0.60 (CI 0.37–0.96), p = 0.034). Whereas, in hypertensives, CAS was not associated with BP level. Multivariate analysis showed that CAS was positively associated with age, male gender, body mass index, myocardial bridge, baseline spasm (narrowing ≥30%) but negatively associated with BP level. Conclusions: These results suggest that Ach-induced CAS is inversely associated with BP level.