Publications by authors named "Philip Shaul"

Dysregulated lipid metabolism is commonly observed in septic patients, but how it contributes to sepsis remains largely unknown. Reverse cholesterol transport (RCT) is crucial for regulating cholesterol metabolism in circulation. During RCT, high-density lipoprotein collects cholesterol from peripheral tissues and transports it to the liver's scavenger receptor BI (SR-BI), where SR-BI mediates the uptake of cholesteryl esters (CEs) from high-density lipoprotein for excretion via bile.

View Article and Find Full Text PDF

Background: Protein glycosylation is an enzymatic process known to reflect an individual's physiologic state and changes thereof. The impact of metabolic interventions on plasma protein N-glycosylation has only been sparsely investigated.

Objective: To examine alterations in plasma protein N-glycosylation following changes in caloric intake and bariatric surgery.

View Article and Find Full Text PDF

Objective: Sialic acid is a terminal monosaccharide of glycans in glycoproteins and glycolipids, and its derivation from glucose is regulated by the rate-limiting enzyme UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE). Although the glycans on key endogenous hepatic proteins governing glucose metabolism are sialylated, how sialic acid synthesis and sialylation in the liver influence glucose homeostasis is unknown. Studies were designed to fill this knowledge gap.

View Article and Find Full Text PDF

Glucocorticoid (GC) therapy had been strongly recommended for pediatric sepsis (grade 1A). However, the recommendation was changed to grade 2C in 2020 due to weak evidence. About 32.

View Article and Find Full Text PDF

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the persistent presence of antibodies directed against phospholipids and phospholipid-binding proteins that are associated with thrombosis and pregnancy-related morbidity. The latter includes fetal deaths, premature birth and maternal complications. In the early 1990s, a distinct set of autoantibodies, termed collectively antiphospholipid antibodies (aPL), were identified as the causative agents of this disorder.

View Article and Find Full Text PDF

The estrogen receptor (ER) designated ERα has actions in many cell and tissue types that impact glucose homeostasis. It is unknown if these include mechanisms in endothelial cells, which have the potential to influence relative obesity, and processes in adipose tissue and skeletal muscle that impact glucose control. Here we show that independent of impact on events in adipose tissue, endothelial ERα promotes glucose tolerance by enhancing endothelial insulin transport to skeletal muscle.

View Article and Find Full Text PDF

Hypercholesterolemia and vascular inflammation are key interconnected contributors to the pathogenesis of atherosclerosis. How hypercholesterolemia initiates vascular inflammation is poorly understood. Here we show in male mice that hypercholesterolemia-driven endothelial activation, monocyte recruitment and atherosclerotic lesion formation are promoted by a crosstalk between macrophages and endothelial cells mediated by the cholesterol metabolite 27-hydroxycholesterol (27HC).

View Article and Find Full Text PDF

Two common features of dietary polyphenols have hampered our mechanistic understanding of their beneficial effects for decades: targeting multiple organs and extremely low bioavailability. We show here that resveratrol intervention (REV-I) in high-fat diet (HFD)-challenged male mice inhibits chylomicron secretion, associated with reduced expression of jejunal but not hepatic scavenger receptor class B type 1 (SR-B1). Intestinal mucosa-specific SR-B1 mice on HFD-challenge exhibit improved lipid homeostasis but show virtually no further response to REV-I.

View Article and Find Full Text PDF

Low-density lipoprotein (LDL) accumulation in the arterial wall contributes to atherosclerosis initiation and progression. Activin A receptor-like type 1 (ACVRL1, called activin-like kinase receptor (ALK1)) is a recently identified receptor that mediates LDL entry and transcytosis in endothelial cells (ECs). However, the role of this pathway in vivo is not yet known.

View Article and Find Full Text PDF
Article Synopsis
  • Cytokine release syndrome (CRS) is a serious sickness that can happen when the immune system gets too excited, either from an infection or from medications, and it can make people really sick or even cause death.
  • Scientists studied mice to find out why some people are at a higher risk of severe CRS, especially focusing on how the adrenal glands (which help manage stress) are linked to this problem.
  • They discovered that giving mice a type of medicine called glucocorticoids (GC) before they got CRS helped keep them safe and alive, suggesting that people with a similar adrenal issue could also benefit from this treatment to avoid severe CRS.
View Article and Find Full Text PDF
Article Synopsis
  • A lot of patients who get really sick from infections (sepsis) also have a problem called relative adrenal insufficiency (RAI), which means their bodies don't make enough stress-fighting hormones.
  • The scientists made special mice that can't produce these hormones to study how RAI affects sepsis, and they found that these RAI mice were much more likely to die from an infection than regular mice.
  • Treating the RAI mice with a little bit of stress hormone helped them survive, but giving this treatment to healthy mice actually made them worse, showing that treatment needs to be different for different patients.
View Article and Find Full Text PDF
Article Synopsis
  • Cholesterol influences the growth of breast cancer, particularly in estrogen receptor-negative (ER-) types, by being converted into 27-hydroxycholesterol (27HC), which is linked to increased cell proliferation.
  • Cells silenced for CYP7B1 (an enzyme that metabolizes 27HC) show heightened growth, especially when deprived of certain lipoproteins, highlighting cholesterol's role in breast cancer proliferation.
  • 27HC acts as a ligand for the G Protein-Coupled Estrogen Receptor (GPER), activating pathways like ERK1/2 and NFκB, and its effects on cancer growth depend on the expression of GPER.
View Article and Find Full Text PDF

Under normal conditions, the blood-brain barrier effectively regulates the passage of immune cells into the central nervous system (CNS). However, under pathological conditions such as multiple sclerosis (MS), leukocytes, especially monocytes, infiltrate the CNS where they promote inflammatory demyelination, resulting in paralysis. Therapies targeting the immune cells directly and preventing leukocyte infiltration exist for MS but may compromise the immune system.

View Article and Find Full Text PDF

Neuroinflammation as a result of immune cell recruitment into the central nervous system (CNS) is a key pathogenic mechanism of multiple sclerosis (MS). However, current anti-inflammatory interventions depleting immune cells or directly targeting their trafficking into the CNS can have serious side effects, highlighting a need for better immunomodulatory strategies. We detected increased Reelin concentrations in the serum of patients with MS, resulting in increased endothelial permeability to leukocytes through increased nuclear factor κB-mediated expression of vascular adhesion molecules.

View Article and Find Full Text PDF
Article Synopsis
  • The neonatal mammalian heart can regenerate shortly after birth, but this ability diminishes within the first week as the heart shifts from using anaerobic glycolysis to fatty-acid metabolism for energy.
  • High rates of reactive oxygen species generated during fatty-acid oxidation may cause DNA damage and prevent heart cell (cardiomyocyte) division.
  • Research involving fat-deficient diets and specific genetic modifications in mice demonstrated that inhibiting fatty-acid use enhances cardiomyocyte proliferation and improves heart recovery after damage, suggesting new potential strategies for cardiac regeneration therapy.
View Article and Find Full Text PDF

Impaired insulin-induced microvascular recruitment in skeletal muscle contributes to insulin resistance in type 2 diabetic disease. Previously, quantification of microvascular recruitment at the capillary level has been performed with either the full image or manually selected region-of-interests. These subjective approaches are imprecise, time-consuming, and unsuitable for automated processes.

View Article and Find Full Text PDF

(Mtb) can enter the body through multiple routes, including via specialized transcytotic cells called microfold cells (M cell). However, the mechanistic basis for M cell entry remains undefined. Here, we show that M cell transcytosis depends on the Mtb Type VII secretion machine and its major virulence factor EsxA.

View Article and Find Full Text PDF

Background: Obesity-related hypertension is a common disorder, and attempts to combat the underlying obesity are often unsuccessful. We previously revealed that mice globally deficient in the inhibitory immunoglobulin G (IgG) receptor FcγRIIB are protected from obesity-induced hypertension. However, how FcγRIIB participates is unknown.

View Article and Find Full Text PDF

Atherosclerosis, which underlies life-threatening cardiovascular disorders such as myocardial infarction and stroke, is initiated by passage of low-density lipoprotein (LDL) cholesterol into the artery wall and its engulfment by macrophages, which leads to foam cell formation and lesion development. It is unclear how circulating LDL enters the artery wall to instigate atherosclerosis. Here we show in mice that scavenger receptor class B type 1 (SR-B1) in endothelial cells mediates the delivery of LDL into arteries and its accumulation by artery wall macrophages, thereby promoting atherosclerosis.

View Article and Find Full Text PDF

Objectives: To evaluate the use of super-resolution ultrasound (SR-US) imaging for quantifying microvascular changes in skeletal muscle using a mouse model of type 2 diabetes.

Methods: Study groups were young, standard chow-fed male C57BL/6J mice (lean group) and high fat diet-fed older mice (obese group). After an overnight fast, dynamic contrast-enhanced US imaging was performed on the proximal hind limb adductor muscle group for 10 minutes at baseline and again at 1 and 2 hours during administration of a hyperinsulinemic-euglycemic clamp.

View Article and Find Full Text PDF