The Potential Role of Milk-Fat-Globule Membrane (MFGM) Proteins in Regulating the Size of Milk-Lipid Droplets

The aim of this thesis was to identify protein factors that may regulate the size of lipid droplets in milk. To address this hypothesis, the relative amounts of specific MFGM proteins on lipid droplets fractionated according to size were measured. Protein amounts were estimated by quantitative western blotting and confocal microscopy. By quantitative confocal microscopy, small lipid droplets (1.26 to 2.8 um) sized droplets. Milk-fat-globule-EFG-8 (MFG-E8) protein was more evenly distributed on small, medium and large droplets. In contrast CD36, in both cow and mouse milk, was concentrated on small droplets and absent from large droplets. Based on these data, we postulate that CD36 possibly association with FABP may have a function in small lipid droplet secretion by localizing excessively on the small lipid droplets

The Role of Adipocyte Lipid Droplet Lipolysis in Thermogenesis and Metabolic Health

My thesis was focused on the role of Comparative Gene Identification-58 (CGI-58)-mediated adipocyte lipid droplet (LD) lipolysis in thermogenesis and metabolic health. LD lipolysis in energy-dissipating brown adipose tissue (BAT) was believed to play a central role in cold-induced non-shivering thermogenesis, but this concept has not been tested in whole animal in vivo. We created a mouse line that lacks BAT CGI-58, a coactivator of Adipose Triglyceride Lipase (ATGL) that initiates the first step of cytosolic LD lipolysis by cleaving a fatty acyl chain from a triglyceride (TG) molecule. We found that BAT-specific CGI-58 knockout (BAT-KO) mice defend against the cold normally when food is absent, despite a defect in BAT LD lipolysis. Interestingly, BAT-KO versus control mice display higher body temperature when food is present during cold exposure. This cold adaptation in BAT-KO mice is associated with increases in BAT glucose uptake, insulin sensitivity, white adipose tissue (WAT) browning, energy expenditure, and sympathetic innervation. To identify the sources of fuels for thermogenesis of BAT-KO mice in the fasted state, we hypothesized that WAT lipolysis is a major source of thermogenic fuels during fasting. To test this hypothesis, we genetically inactivated CGI-58 expression in the whole fat tissues (both BAT and WAT) of mice (FAT-KO mice). We observed that FAT-KO mice are cold sensitive when food is absent, but tolerate cold normally when food is present, demonstrating that WAT lipolysis is essential for cold-induced thermogenesis during fasting and that dietary nutrients can substitute WAT lipolysis for fueling whole-body thermogenesis. Intriguingly, FAT-KO mice display a dramatic increase in cardiac glucose uptake under both basal and insulin-stimulated conditions, which is associated with significant increases in glucose tolerance, insulin sensitivity, and cardiac expression levels of natriuretic peptides. In conclusion, our studies demonstrate that 1) BAT LD lipolysis is not essential for cold-induced whole-body thermogenesis due to increased BAT uptake of circulating fuels and WAT browning; 2) WAT lipolysis is required for fueling thermogenesis during fasting; and 3) Adipose lipolysis is critically implicated in whole-body energy metabolism and cardiac function

Improved application of the electrophoretic tissue clearing technology, CLARITY, to intact solid organs including brain, pancreas, liver, kidney, lung, and intestine

Background: Mapping of tissue structure at the cellular, circuit, and organ-wide scale is important for understanding physiological and biological functions. A bio-electrochemical technique known as CLARITY used for three-dimensional anatomical and phenotypical mapping within transparent intact tissues has been recently developed. This method provided a major advance in understanding the structure-function relationships in circuits of the nervous system and organs by using whole-body clearing. Thus, in the present study, we aimed to improve the original CLARITY procedure and developed specific CLARITY protocols for various intact organs. Results: We determined the optimal conditions for reducing bubble formation, discoloration, and depositing of black particles on the surface of tissue, which allowed production of clearer organ images. We also determined the appropriate replacement cycles of clearing solution for each type of organ, and convincingly demonstrated that 250–280 mA is the ideal range of electrical current for tissue clearing. We then acquired each type of cleared organs including brain, pancreas, liver, lung, kidney, and intestine. Additionally, we determined the images of axon fibers of hippocampal region, the Purkinje layer of cerebellum, and vessels and cellular nuclei of pancreas. Conclusions: CLARITY is an innovative biochemical technology for the structural and molecular analysis of various types of tissue. We developed improved CLARITY methods for clearing of the brain, pancreas, lung, intestine, liver, and kidney, and identified the appropriate experimental conditions for clearing of each specific tissue type. These optimized methods will be useful for the application of CLARITY to various types of organs. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0048-3) contains supplementary material, which is available to authorized users

Electroacupuncture Attenuates Ovalbumin-Induced Allergic Asthma via Modulating CD4+CD25+ Regulatory T Cells

A mouse pulmonary hypersensitivity experimental model that mimics human asthma was developed, and electroacupuncture (EA) treatment was shown to reduce allergic inflammatory processes. In addition, we also assessed whether the beneficial effects of EA on allergic asthma could be correlated with CD4+CD25+Foxp3+ regulatory T cells (Treg). Cellular profiles and histopathologic analysis demonstrated that peribronchial and perivascular inflammatory cell infiltrates were significantly decreased in the EA-treated groups when compared to the OVA and anti-CD25 Ab-injected (Treg depletion) groups. Furthermore, total BAL cells were reduced in the EA groups when compared to other groups. Interestingly, the population of CD4+CD25+Foxp3+Tregs in pneumonocytes increased in EA-treated group when compared to OVA and Treg depletion groups. These results imply that EA stimulation at ST 36 may affect CD4+CD25+Foxp3+ Treg in an OVA-induced experimental model and may enhance Treg function by suppressing other T cells and limiting the immune response

BallGAN: 3D-aware Image Synthesis with a Spherical Background

3D-aware GANs aim to synthesize realistic 3D scenes such that they can be rendered in arbitrary perspectives to produce images. Although previous methods produce realistic images, they suffer from unstable training or degenerate solutions where the 3D geometry is unnatural. We hypothesize that the 3D geometry is underdetermined due to the insufficient constraint, i.e., being classified as real image to the discriminator is not enough. To solve this problem, we propose to approximate the background as a spherical surface and represent a scene as a union of the foreground placed in the sphere and the thin spherical background. It reduces the degree of freedom in the background field. Accordingly, we modify the volume rendering equation and incorporate dedicated constraints to design a novel 3D-aware GAN framework named BallGAN. BallGAN has multiple advantages as follows. 1) It produces more reasonable 3D geometry; the images of a scene across different viewpoints have better photometric consistency and fidelity than the state-of-the-art methods. 2) The training becomes much more stable. 3) The foreground can be separately rendered on top of different arbitrary backgrounds.Comment: Project Page: https://minjung-s.github.io/ballga

CD4+CD25+ regulatory T cells attenuate cisplatin-induced nephrotoxicity in mice

Nephrotoxicity limits the use of cisplatin, a widely used chemotherapeutic agent for treatment of various malignancies. Overall, CD4+ T cells mediate cisplatin-induced renal injury; however, the CD4+CD25+ regulatory T-cell subset (CD4+CD25+ Treg) has broad suppressive effects on many different cell types. In this study, we determined whether CD4+CD25+ Treg cells had protective effects against cisplatin-induced acute renal injury in nu/nu mice that lack mature T cells. In these mice, there was marked attenuation of the decreased survival, renal dysfunction and tubular injury, renal tumor necrosis factor-α, and interleukin-1β cytokine levels. Furthermore, renal macrophage accumulation was reduced in CD4+CD25+ Treg cell-adoptive transferred nu/nu mice compared with control mice. Infusion of CD4+CD25+Treg cells into wild-type Balb/c mice reduced serum blood urea nitrogen and creatinine levels equivalent to those in nu/nu mice and extended their survival time after cisplatin injection. In contrast, depletion of CD4+CD25+ Treg cells in wild-type mice exacerbated kidney injury after cisplatin administration. Transcription factor Foxp3-positive cells (Treg cells) were detected in the kidneys of nu/nu mice after cisplatin injection. Our results suggest that CD4+CD25+ Treg cells directly affect cisplatin nephrotoxicity and their modulation represents an additional treatment strategy

A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γ levels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific

NPC1L1 knockout protects against colitis-associated tumorigenesis in mice

Colorectal cancer is strongly associated with lipid metabolism. NPC1L1, a sterol transporter, plays a key role in modulating lipid homeostasis in vivo. Its inhibitor, ezetimibe, began to be used clinically to lower cholesterol and this caused the great debate on its role in causing carcinogenesis. Here we explored the role of NPC1L1 in colorectal tumorigenesis. Wild-type mice and NPC1L1−/− (NPC1L1 knockout) mice were treated with azoxymethane (AOM)-dextran sodium sulfate (DSS) to induce colitis-associated colorectal tumorigenesis. Mice were sacrificed 10, 15, 18 or 20 weeks after AOM treatment, respectively. Colorectal tumors were counted and analyzed. Plasma lipid concentrations were measured using enzymatic reagent kit. Protein expression level was assayed by western blot. NPC1L1−/− mice significantly had fewer tumors than wild-type. The ratio of malignant/tumor in NPC1L1−/− mice was significantly lower than in wild-type 20 weeks after AOM-DSS treatment. NPC1L1 was highly expressed in the small intestine of wild-type mice but its expression was undetectable in colorectal mucous membranes or tumors in either group. NPC1L1 knockout decreased plasma total cholesterol and phospholipid. NPC1L1−/− mice had significant lower intestinal inflammation scores and expressed inflammatory markers p-c-Jun, p-ERK and Caspase-1 p20 lower than wild-type. NPC1L1 knockout also reduced lymphadenectasis what may be caused by inflammation. NPC1L1 knockout in mice decreased β-catenin in tumors and regulated TGF-β and p-gp in adjacent colons or tumors. There was not detectable change of p53 by NPC1L1 knockout. Our results provide the first evidence that NPC1L1 knockout protects against colitis-associated tumorigenesis. NPC1L1 knockout decreasing plasma lipid, especially cholesterol, to reduce inflammation and decreasing β-catenin, p-c-Jun and p-ERK may be involved in the mechanism.https://doi.org/10.1186/s12885-015-1230-

Dose-Dependent Neuroprotective Effect of Standardized Bee Venom Phospholipase A2 Against MPTP-Induced Parkinson’s Disease in Mice

Parkinson’s disease (PD) is a chronic progressive neurodegenerative movement disorder characterized by the selective loss of dopaminergic neurons within the substantia nigra (SN). While the precise etiology of dopaminergic neuronal demise is elusive, multiple lines of evidence indicate that neuroinflammation is involved in the pathogenesis of PD. We have previously demonstrated that subcutaneous administration of bee venom (BV) phospholipase A2 (bvPLA2) suppresses dopaminergic neuronal cell death in a PD mouse model. In the present study, we established standardized methods for producing bvPLA2 agent isolated from crude BV at good manufacturing practice (GMP) facility. The therapeutic efficacy of purified bvPLA2 agent was examined in MPTP-induced PD mice. Importantly, administration of purified bvPLA2 in a dose-dependent manner reversed motor deficits in PD mice as well as inhibited loss of dopaminergic neurons within the SN of PD mice. The concentration-dependent action of standardized bvPLA2 appeared to be related to the induction of CD4+CD25+Foxp3+ regulatory T cells (Tregs), which, in part, inhibits T helper 1 (Th1) and Th17 polarization and suppresses microglial activation in PD mice. Taken together, these results suggest that standardized bvPLA2 purified from BV shows a neuroprotective effect against PD and thus has a potential target for treatment of PD

Elevated IFNA1 and suppressed IL12p40 associated with persistent hyperinflammation in COVID-19 pneumonia

IntroductionDespite of massive endeavors to characterize inflammation in COVID-19 patients, the core network of inflammatory mediators responsible for severe pneumonia stillremain remains elusive. MethodsHere, we performed quantitative and kinetic analysis of 191 inflammatory factors in 955 plasma samples from 80 normal controls (sample n = 80) and 347 confirmed COVID-19 pneumonia patients (sample n = 875), including 8 deceased patients. ResultsDifferential expression analysis showed that 76% of plasmaproteins (145 factors) were upregulated in severe COVID-19 patients comparedwith moderate patients, confirming overt inflammatory responses in severe COVID-19 pneumonia patients. Global correlation analysis of the plasma factorsrevealed two core inflammatory modules, core I and II, comprising mainly myeloid cell and lymphoid cell compartments, respectively, with enhanced impact in a severity-dependent manner. We observed elevated IFNA1 and suppressed IL12p40, presenting a robust inverse correlation in severe patients, which was strongly associated with persistent hyperinflammation in 8.3% of moderate pneumonia patients and 59.4% of severe patients. DiscussionAberrant persistence of pulmonary and systemic inflammation might be associated with long COVID-19 sequelae. Our comprehensive analysis of inflammatory mediators in plasmarevealed the complexity of pneumonic inflammation in COVID-19 patients anddefined critical modules responsible for severe pneumonic progression