New insights into X-linked adrenal hypoplasia congenita from a novel splice-site variant of NR0B1 and adrenal CT images.

BACKGROUND: X-linked adrenal hypoplasia congenita (AHC) is a rare disorder, often manifesting as primary adrenal insufficiency (PAI) and hypogonadotropic hypogonadism (HH), and caused by variants of NR0B1, most of which are frame-shifting variants, and few splice-site variants. METHODS AND RESULTS: Here, a novel splice-site variant of NR0B1 (NM_000475.4), c.1169-2A>T (patient 1), and a stop-loss variant of NR0B1 c.1411T>C (patient 2) are described in this study. We perform minigene assays for the splice-site variant (c.1169-2A>T) and determine that the variant causes exon 2 skipping. Moreover, the defect of NR0B1 protein may bring about the severe phenotype of the patient. Through 8 years of follow-up, we compare the CT images from 8 years ago with the latest image, and observe the CT image change of adrenal in patient 2 (from the increased thickness of adrenal to adrenal atrophy). CONCLUSION: X-linked adrenal hypoplasia congenita is produced by variants of NR0B1. We report a case that presents a novel splice-site variant, which has been verified that it could lead to the exon 2 skipping in the RNA splicing progress. Moreover, we report the adrenal CT image change of patient 2, which has never been referred to before, and expand the spectrum of X-linked AHC characteristics.

Scalable submicrometer additive manufacturing.

High-throughput fabrication techniques for generating arbitrarily complex three-dimensional structures with nanoscale features are desirable across a broad range of applications. Two-photon lithography (TPL)-based submicrometer additive manufacturing is a promising candidate to fill this gap. However, the serial point-by-point writing scheme of TPL is too slow for many applications. Attempts at parallelization either do not have submicrometer resolution or cannot pattern complex structures. We overcome these difficulties by spatially and temporally focusing an ultrafast laser to implement a projection-based layer-by-layer parallelization. This increases the throughput up to three orders of magnitude and expands the geometric design space. We demonstrate this by printing, within single-digit millisecond time scales, nanowires with widths smaller than 175 nanometers over an area one million times larger than the cross-sectional area.

Compact high-resolution endomicroscopy based on fiber bundles and image stitching.

In this Letter, we report a compact endomicroscope (ϕ=2.8 mm) based on a fiber bundle and a two-axis piezoelectric tube scanner, achieving a resolution of ∼1 µm and an imaging speed of 30-120 fps. Compared with distal end scanning systems, typical fiber-bundle-based endomicroscopes achieve a more compact envelope (ϕ∼1.5 mm) at the expense of compromised imaging quality. The resolution of fiber-bundle-based systems is largely limited by the diameter of the constituent fibers (ϕ∼5.0 µm), where each fiber serves as a single pixel, i.e., a sampling point, in the imaging system. To retrieve the lost information, we integrate a piezo tube scanner at the tip of the fiber bundle. Next, we rapidly scan the fiber tip over a range of ±2.5 µm and combine the signals obtained at different inter-fiber locations. Direct alignment and feature-based registration methods are applied to register the raw images. Imaging experiments are performed on a resolution target and biological samples to demonstrate the performance enhancement.

The effect of cholesteryl ester transfer protein on pancreatic beta cell dysfunction in mice.

BACKGROUND: Cholesterol accumulation causes pancreatic beta cell lipotoxicity and dysfunction. Cholesteryl ester transfer protein (CETP) plays an important role in blood lipid homeostasis. However, its role in tissue lipid metabolism remains unclear. We hypothesized that plasma CETP impact cholesterol homeostasis in the beta cells, thus damaging their functions. METHODS: The adipose tissue-specific CETP expression transgenic (aP2-CETPTg) mice, characterized by high CETP levels in the circulation, were used in this study. Pancreatic islet cholesterol and beta cell function were assessed in mice. We further measured mRNA levels of the genes involved in beta cell proliferation and differentiation, inflammation and cholesterol metabolism. TUNEL assay was applied to investigate beta cell apoptosis in islets. RESULTS: The aP2-CETPTg mice exhibited glucose intolerance, lower plasma insulin concentrations but increased insulin sensitivity compared with wild type mice. In addition, glucose-stimulated insulin secretion from isolated pancreatic islets significantly decreased, and free cholesterol significantly increased. Moreover, the number and size of islets from aP2-CETPTg mice were significantly decreased. Genes involved in beta cell proliferation, such as Pdx1 and BETA2, were down-regulated; genes involved in inflammation and ER stress, such as IL-1ß, CHOP, and Xbp1 were up-regulated, in line with an increase of beta cell apoptosis. CONCLUSIONS: Plasma CETP causes free cholesterol accumulation in islets which could contribute to beta cell dysfunction. Thus, CETP inhibition could be a novel protective strategy for dyslipidemia related to diabetes and obese.

Femtosecond laser pulse shaping at megahertz rate via a digital micromirror device.

In this Letter, we present a scanner and digital micromirror device (DMD)-based ultrafast pulse shaper, i.e., S-DUPS, for programmable ultrafast pulse modulation, achieving a shaping rate of 2 MHz. To our knowledge, the S-DUPS is the fastest programmable pulse shaper reported to date. In the S-DUPS, the frequency spectrum of the input pulsed laser is first spread horizontally, and then mapped to a thin stripe on the DMD programmed with phase modulation patterns. A galvanometric scanner, synchronized with the DMD, subsequently scans the spectrum vertically on the DMD to achieve a shaping rate up to 10 s MHz. A grating pair and a cylindrical lens in front of the DMD compensate for the temporal and spatial dispersion of the system. To verify the concept, experiments were conducted with the DMD and the galvanometric scanner operated at 2 kHz and 1 kHz, respectively, achieving a 2 MHz speed for continuous group velocity dispersion tuning, as well as 2% efficiency. Up to 5% efficiency of S-DUPS can be expected with high efficiency gratings and optical components of proper coatings.

Digital micromirror device-based ultrafast pulse shaping for femtosecond laser.

In this Letter, we present a new digital micromirror device (DMD)-based ultrafast pulse shaper, i.e., DUPS. To the best of our knowledge, the DUPS is the first binary pulse shaper that can modulate high repetition rate laser sources at up to a 32 kHz rate (limited by the DMD pattern rate). Since pulse modulation occurs in the frequency domain through reflective two-dimensional micromirror arrays, i.e., DMD, the DUPS is not only compact and low in cost, but also possesses a high damage threshold that is critical for high pulse energy laser applications. In this work, a grating pair was introduced in the DUPS to compensate the DMD induced dispersion. Double pulses were generated to validate the effectiveness of the DUPS and calibrate the system. Subsequently, we demonstrated arbitrary phase shaping capability by continuous tuning of group velocity dispersion (GVD) and modulation of half-spectrum shifted by π. The overall efficiency was measured to be 1.7%, while an efficiency of up to 5% can be expected when high efficiency gratings and properly coated DMDs are used.

Human cholesteryl ester transfer protein enhances insulin-mediated glucose uptake in adipocytes.

AIMS: Adipose tissue plays an important role in the pathogenesis of insulin resistance, obesity, and Type-2 diabetes. Human adipocytes express abundant cholesteryl ester transfer protein (CETP). However, the function and role of CETP in regulating lipoprotein metabolism are mostly unknown. In this study, we examined whether CETP affected the insulin-mediated responses in adipocytes. MAIN METHODS: Because mouse 3T3-L1 preadipocytes do not express CETP, we established a stable cell line expressing human CETP by transfecting the cells with pcDNA3.1/human CETP. We used a standard approach to differentiate the cells into mature adipocytes, and we examined the cholesterol balance and insulin responses. KEY FINDINGS: The human CETP stable cell line expressed stable levels of CETP without affecting the expression of either peroxisome proliferator-activated receptor-gamma (PPARγ) or glucose transporter-4 (GLUT4) throughout cell differentiation. CETP expression significantly increased the level of both total and free cholesterol in the mature adipocytes. Upon insulin stimulation, CETP expressing cells had significantly higher protein kinase B (Akt) phosphorylation and 2-(3)H-deoxyglucose uptake, as compared with 3T3-L1 cells and cells transfected with control vector. SIGNIFICANCE: Human CETP expression increased cellular cholesterol levels and enhanced insulin-stimulated Akt phosphorylation and glucose uptake in adipocytes. Thus, CETP may modulate glucose metabolism and insulin action in addition to its effects on lipoprotein metabolism.