Publications by authors named "Vijayalakshmi Varma"

Background: Psoriasis is a chronic inflammatory condition associated with coronary artery disease risk. Uptake of oxidized low-density lipoprotein by the lectin-like low-density lipoprotein receptor-1 triggers release of the soluble extracellular domain of the receptor (sLOX-1). We sought to characterize the relationship between sLOX-1, inflammation, and coronary plaque progression in psoriasis.

View Article and Find Full Text PDF

Background Blockade of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a potentially attractive mechanism for lowering inflammatory and lipid risk in patients with atherosclerosis. This study aims to assess the safety, tolerability, and target engagement of MEDI6570, a high-affinity monoclonal blocking antibody to LOX-1. Methods and Results This phase 1, first-in-human, placebo-controlled study (NCT03654313) randomized 88 patients with type 2 diabetes to receive single ascending doses (10, 30, 90, 250, or 500 mg) or multiple ascending doses (90, 150, or 250 mg once monthly for 3 months) of MEDI6570 or placebo.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is the fourth leading cause of death in the United States and the most common cause of adult-onset dementia. Recent results suggest an increased prevalence and severity in African Americans compared to Caucasians. Our understanding of the potential mechanism(s) underlying this ethnicity difference is limited.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how fructose affects the metabolism of pre-adipocytes compared to glucose, focusing on changes in DNA methylation and gene expression during adipocyte differentiation.
  • Time-dependent analysis revealed significant differences in DNA methylation patterns, with fructose-supplemented medium showing less variation in DMRs compared to glucose-added medium, indicating distinct regulatory mechanisms at play.
  • Lower concentrations of fructose (2.5 mM) were found to have a more pronounced impact on DNA methylation than higher concentrations (5 and 10 mM), suggesting that fructose may act as a signaling molecule at lower levels while serving primarily as a nutrient at higher levels.
View Article and Find Full Text PDF

Chronic neuroinflammation is strongly associated with AD and altered peripheral and central levels of chemokines and cytokines have been frequently described in those with AD. Given the increasing evidence of ethnicity-related differences in AD, it was of interest to determine if those altered chemokine and cytokine levels are ethnicity-related. Because African Americans exhibit a higher incidence of AD and increased symptom severity, we explored chemokine and cytokine concentrations in post-mortem brain tissue from the BA21 region of African Americans and Caucasians with AD using multiplex assays.

View Article and Find Full Text PDF
Article Synopsis
  • Lipids are essential for cell functions, including signaling and energy storage, and make up a big part of cell membranes; however, research on how lipid compositions vary by tissue type is limited.
  • This pilot study used a new tool called the Lipidyzer to analyze lipid profiles in liver and heart tissues of mice, focusing on the differences based on sex and biological variability.
  • The study found significant differences in lipid levels, such as variations in cholesterol esters between males and females in the liver, and higher levels of specific phospholipids in cardiac tissues, indicating the Lipidyzer's effectiveness in this type of research.
View Article and Find Full Text PDF

Background: Alzheimer's disease (AD) presents with an earlier onset age and increased symptom severity in African Americans and Hispanics.

Objective: Although the prevalence of plaques and tangles may not exhibit ethnicity-related differences, levels of neurodegenerative proteins have not been described.

Methods: Here, levels of five proteins (i.

View Article and Find Full Text PDF

The investigation of the complex processes involved in cellular differentiation must be based on unbiased, high throughput data processing methods to identify relevant biological pathways. A number of bioinformatics tools are available that can generate lists of pathways ranked by statistical significance (i.e.

View Article and Find Full Text PDF

Objective: Micro RNAs (miRNAs) are a class of non-coding regulatory RNAs. We performed a transcriptome-wide analysis of subcutaneous adipose tissue and in vitro studies to identify miRNAs and co-regulated target transcripts associated with insulin sensitivity (SI) and obesity in human.

Methods: We selected 20 insulin-resistant (IR, SI=2.

View Article and Find Full Text PDF

Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS) preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration.

View Article and Find Full Text PDF

The development of obesity is becoming an international problem and the role of fructose is unclear. Studies using liver tissue and hepatocytes have contributed to the understanding of fructose metabolism. Excess fructose consumption also affects extra hepatic tissues including adipose tissue.

View Article and Find Full Text PDF

The endoplasmic reticulum (ER) of adipocytes plays a major role in the assembly and secretion of adipokines. The levels of serum adiponectin, secreted by adipocytes, are decreased in insulin resistance, diabetes, and obesity. The role of ER stress in downregulating adiponectin levels has been demonstrated in mouse models of obesity.

View Article and Find Full Text PDF

Macrophages are an important component of muscle where they are involved in complex processes such as repair, regeneration and hypertrophy. We recently reported that macrophage numbers increase in the muscle of obese patients, suggesting that muscle-resident macrophages could be involved in the development of muscle insulin resistance that is associated with obesity. Coculture of activated macrophages with human muscle cells impairs insulin signaling and induces atrophy signaling pathways in the human muscle cells; this is exacerbated by the addition of palmitic acid.

View Article and Find Full Text PDF

Throughout the last century, possible effects of exposure to toxicants, nutrients or drugs were examined primarily by studies of groups or populations. Individual variation in responses was acknowledged but could not be analyzed due to lack of information or tools to analyze individual genetic make-ups and lifestyle factors such as diet and activity. The Human Genome, Haplotype Map, 1000Genomes, and Human Variome Projects are identifying and cataloging the variation found within humans.

View Article and Find Full Text PDF

Adipose triglyceride lipase (ATGL) catalyzes the first step in adipocyte and muscle triglyceride hydrolysis, and comparative gene identification-58 (CGI-58) is an essential cofactor. We studied the expression of ATGL and CGI-58 in human adipose and muscle and examined correlations with markers of muscle fatty acid oxidation. Nondiabetic volunteers were studied.

View Article and Find Full Text PDF

Background: Recent advances in high-throughput genotyping technology are paving the way for research in personalized medicine and nutrition. However, most of the genetic markers identified from association studies account for a small contribution to the total risk/benefit of the studied phenotypic trait. Testing whether the candidate genes identified by association studies are causal is critically important to the development of personalized medicine and nutrition.

View Article and Find Full Text PDF

Increasing consumption of refined carbohydrates is now being recognized as a primary contributor to the development of nutritionally related chronic diseases such as obesity and type 2 diabetes mellitus (T2DM). A data mining approach was used to evaluate the role of carbohydrate metabolic pathway genes in the development of obesity and T2DM. Data from public databases were used to map the position of the carbohydrate metabolic pathway genes to known quantitative trait loci (QTL) for obesity and T2DM and for examining the pathway genes for the presence of sequence and structural genetic variants such as single nucleotide polymorphisms (SNPs) and copy number variants (CNS), respectively.

View Article and Find Full Text PDF

Context: The study investigated the regulation of matrix metalloproteinases (MMP)-9 in obesity-associated insulin resistance in humans.

Objectives: The objectives of the investigation were to study MMP-9 regulation by insulin resistance and pioglitazone treatment in impaired glucose tolerant subjects using adipose tissue biopsies and study the mechanism of MMP-9 regulation by pioglitazone in adipocyte cultures.

Research Design: 86 nondiabetic, weight-stable subjects between 21 and 66 yr of age were recruited in a university hospital research center setting.

View Article and Find Full Text PDF

Objective: Scavenger receptors play crucial roles in the pathogenesis of atherosclerosis, but their role in insulin resistance has not been explored. We hypothesized that scavenger receptors are present in human adipose tissue resident macrophages, and their gene expression is regulated by adiponectin and thaizolidinediones.

Methods And Results: The gene expression of scavenger receptors including scavenger receptor-A (SRA), CD36, and lectin-like oxidized LDL receptor-1 (LOX-1) were studied in subcutaneous adipose tissue of nondiabetic subjects and in vitro.

View Article and Find Full Text PDF

Obesity is characterized by adipose tissue expansion as well as macrophage infiltration of adipose tissue. This results in an increase in circulating inflammatory cytokines and nonesterified fatty acids, factors that cause skeletal muscle insulin resistance. Whether obesity also results in skeletal muscle inflammation is not known.

View Article and Find Full Text PDF

Context And Objective: Stearoyl-coenzyme A desaturase (SCD1) is the rate-limiting enzyme that converts palmitoyl- and stearoyl-coenzyme A to palmitoleoyl- and oleoyl-cownzyme A, respectively. SCD-deficient mice are protected from obesity, and the ob/ob mouse has high levels of SCD. This study was designed to better characterize SCD1 gene and protein expression in humans with varying insulin sensitivity.

View Article and Find Full Text PDF

Objective: We examined the relationship between the expression of thrombospondin (TSP)1, an antiangiogenic factor and regulator of transforming growth factor-beta activity, obesity, adipose inflammation, and insulin resistance.

Research Design And Methods: TSP1 gene expression was quantified in subcutaneous adipose tissue (SAT) of 86 nondiabetic subjects covering a wide range of BMI and insulin sensitivity, from visceral adipose (VAT) and SAT from 14 surgical patients and from 38 subjects with impaired glucose tolerance randomized to receive either pioglitazone or metformin for 10 weeks. An adipocyte culture system was also used to assess the effects of pioglitazone and coculture with macrophages on TSP1 gene expression.

View Article and Find Full Text PDF

Context: Retinol binding protein 4 (RBP4) was recently found to be expressed and secreted by adipose tissue, and was strongly associated with insulin resistance.

Objective: The aim was to determine the relationship between RBP4 and obesity, insulin resistance, and other markers of insulin resistance in humans.

Design And Patients: RBP4 mRNA levels in adipose tissue and muscle of nondiabetic human subjects with either normal or impaired glucose tolerance (IGT) were studied, along with plasma RBP4.

View Article and Find Full Text PDF

Lipid droplet proteins of the PAT (perilipin, adipophilin, and TIP47) family regulate cellular neutral lipid stores. We have studied a new member of this family, PAT-1, and found that it is expressed in highly oxidative tissues. We refer to this protein as "OXPAT.

View Article and Find Full Text PDF

Context: Visfatin (VF) is a recently described adipokine preferentially secreted by visceral adipose tissue (VAT) with insulin mimetic properties.

Objective: The aim of this study was to examine the association of VF with insulin sensitivity, intramyocellular lipids (IMCL), and inflammation in humans.

Design And Patients: VF mRNA was examined in paired samples of VAT and abdominal sc adipose tissue (SAT) obtained from subjects undergoing surgery.

View Article and Find Full Text PDF