Whole-Genome Sequencing of Finnish Type 1 Diabetic Siblings Discordant for Kidney Disease Reveals DNA Variants associated with Diabetic Nephropathy.

Background: Several genetic susceptibility loci associated with diabetic nephropathy have been documented, but no causative variants implying novel pathogenetic mechanisms have been elucidated.

Methods: We carried out whole-genome sequencing of a discovery cohort of Finnish siblings with type 1 diabetes who were discordant for the presence (case) or absence (control) of diabetic nephropathy. Controls had diabetes without complications for 15-37 years.

In Vivo Generation of Post-infarct Human Cardiac Muscle by Laminin-Promoted Cardiovascular Progenitors.

Regeneration of injured human heart muscle is limited and an unmet clinical need. There are no methods for the reproducible generation of clinical-quality stem cell-derived cardiovascular progenitors (CVPs). We identified laminin-221 (LN-221) as the most likely expressed cardiac laminin.

Culturing functional pancreatic islets on α5-laminins and curative transplantation to diabetic mice.

The efficacy of islet transplantation for diabetes treatment suffers from lack of cadaver-derived islets, islet necrosis and long transfer times prior to transplantation. Here, we developed a method for culturing mouse and human islets in vitro on α5-laminins, which are natural components of islet basement membranes. Adhering islets spread to form layers of 1-3 cells in thickness and remained normoxic and functional for at least 7 days in culture.

Membrane-Tethered Metalloproteinase Expressed by Vascular Smooth Muscle Cells Limits the Progression of Proliferative Atherosclerotic Lesions.

Background: The MMP (matrix metalloproteinase) family plays diverse and critical roles in directing vascular wall remodeling in atherosclerosis. Unlike secreted-type MMPs, a member of the membrane-type MMP family, MT1-MMP (membrane-type 1 MMP; MMP14), mediates pericellular extracellular matrix degradation that is indispensable for maintaining physiological extracellular matrix homeostasis. However, given the premature mortality exhibited by MT1-MMP-null mice, the potential role of the proteinase in atherogenesis remains elusive.

CerS2 haploinsufficiency inhibits β-oxidation and confers susceptibility to diet-induced steatohepatitis and insulin resistance.

Inhibition of ceramide synthesis prevents diabetes, steatosis, and cardiovascular disease in rodents. Six different ceramide synthases (CerS) that differ in tissue distribution and substrate specificity account for the diversity in acyl-chain composition of distinct ceramide species. Haploinsufficiency for ceramide synthase 2 (CerS2), the dominant isoform in the liver that preferentially makes very-long-chain (C22/C24/C24:1) ceramides, led to compensatory increases in long-chain C16-ceramides and conferred susceptibility to diet-induced steatohepatitis and insulin resistance.

P-selectin glycoprotein ligand-1 deficiency leads to cytokine resistance and protection against atherosclerosis in apolipoprotein E deficient mice.

Adhesive interactions between endothelial cells and leukocytes contribute to atherosclerotic plaque growth. However, mechanism(s) responsible for endothelial priming and deactivation in inflammatory diseases such as atherosclerosis are not clear. Apolipoprotein E deficient mice were generated with deficiency of P-selectin glycoprotein ligand-1 (Psgl-1(-/-), ApoE(-/-)).

Leptin receptor-induced STAT3-independent signaling pathways are protective against atherosclerosis in a murine model of obesity and hyperlipidemia.

Aims: Leptin is an adipocyte-derived hormone that has been shown to exert both beneficial metabolic effects and potentially adverse vascular effects in preclinical studies. The primary aim of this study was to determine the effects of leptin receptor signaling pathways on atherosclerosis in the setting of obesity and hyperlipidemia.

Methods And Results: Mice were generated with deficiency of apolipoprotein E (ApoE(-/-)) and either wild-type leptin receptor expression (Lepr(+/+), ApoE(-/-)), mutant leptin receptor expression defective in all leptin receptor signaling pathways (Lepr(db/db), ApoE(-/-)), or mutant leptin receptor expression with selective deficiency of leptin receptor-STAT3 signaling (Lepr(s/s), ApoE(-/-)).

Atherosclerosis and leukocyte-endothelial adhesive interactions are increased following acute myocardial infarction in apolipoprotein E deficient mice.

Objective: To determine the effect of myocardial infarction (MI) on progression of atherosclerosis in apolipoprotein E deficient (ApoE-/-) mice.

Methods And Results: MI was induced following left anterior descending coronary artery (LAD) ligation in wild-type (WT) (n=9) and ApoE-/- (n=25) mice. Compared to sham-operated animals, MI mice demonstrated increased intravascular leukocyte rolling and firm adhesion by intravital microscopy, reflecting enhanced systemic leukocyte-endothelial interactions.

P-selectin glycoprotein ligand-1 regulates adhesive properties of the endothelium and leukocyte trafficking into adipose tissue.

Rationale: Adhesive interactions between endothelial cells and leukocytes affect leukocyte trafficking in adipose tissue. The role of P-selectin glycoprotein ligand-1 (Psgl-1) in this process is unclear.

Objective: The goal of this study was to determine the effect of Psgl-1 deficiency on adhesive properties of the endothelium and on leukocyte recruitment into obese adipose depots.

Monocyte chemoattractant protein-1 deficiency protects against visceral fat-induced atherosclerosis.

Objective: To determine the role of monocyte chemoattractant protein-1 (Mcp-1) on the progression of visceral fat-induced atherosclerosis.

Methods And Results: Visceral fat inflammation was induced by transplantation of perigonadal fat. To determine whether recipient Mcp-1 status affected atherosclerosis induced by inflammatory fat, apolipoprotein E-deficient (ApoE(-/-)) and ApoE(-/-) and Mcp-1-deficient (Mcp-1(-/-)) mice underwent visceral fat transplantation.

Targeting MCP-1 to reduce vascular complications of obesity.

Obesity is a risk factor for complications of atherosclerotic vascular disease such as myocardial infarction. Recent studies and several patents have demonstrated that the cardiovascular risk associated with obesity is correlated particularly with visceral adiposity. Excess visceral adiposity may increase vascular risk due to secretion of cytokines and chemokines by cellular constituents of the adipose tissue.

Visceral adipose tissue and atherosclerosis.

Obesity is a risk factor for complications of atherosclerotic vascular disease such as myocardial infarction and stroke. Recent studies have demonstrated that the vascular risk associated with obesity is correlated particularly with visceral adiposity. These clinical observations indicate that various adipose tissue depots may have differential effects on vascular risk.

Visceral adipose tissue inflammation accelerates atherosclerosis in apolipoprotein E-deficient mice.

Background: Fat inflammation may play an important role in comorbidities associated with obesity such as atherosclerosis.

Methods And Results: To first establish feasibility of fat transplantation, epididymal fat pads were harvested from wild-type C57BL/6J mice and transplanted into leptin-deficient (Lep(ob/ob)) mice. Fat transplantation produced physiological leptin levels and prevented obesity and infertility in Lep(ob/ob) mice.