Resolvin E1 actions on polymorphonuclear neutrophils in diabetes

Dissertation (DScD) -- Boston University, Henry M. Goldman School of Dental Medicine, 2010 (Department of Periodontology and Oral Biology).Diabetes and periodontal disease exhibit a bidirectional relationship centered on an enhanced inflammatory response manifested both locally and systemically. The observation that hyperglycemia by itself, in the absence of additional inflammatory signals, promotes a proinflammatory environment indicates that diabetes is an independent risk factor for periodontal disease. Leukocyte pre-activation or priming in diabetes has been demonstrated. Excessive ROS release by leukocytes, upregulation of pro-inflammatory mediators and adhesion molecules are characteristic to T2DM-associated low-grade inflammation. However, the mechanisms by which chronic hyperglycemia leads to leukocyte activation are not fully understood. [TRUNCATED

Rac Null Leukocytes Are Associated With Increased Inflammation-mediated Alveloar Bone Loss

Genetic and epigenetic factors that predispose to ineffective control of subgingival biofilm composition are incompletely understood. The objective of this study was to elucidate how leukocytes impact on the course of periodontitis in Rac-null mice. Models of acute gingivitis and periodontitis were used to assess the early inflammatory response and patterns of chronicity leading to alveolar bone loss. Leukocyte margination was differentially impaired during attachment in conditional Rac1-null and during rolling and attachment in Rac2-null mice. The inflammatory responses to subgingival ligatures were altered in Rac-null compared to WT mice. In response to persistent subgingival challenge Rac-null mice had increased alveolar bone loss with resorption patterns characteristic to aggressive periodontitis, partially explained by higher osteoclastic activity in Rac-null mice. This study demonstrates that migratory leukocyte defects are rate limiting steps in the periodontal inflammatory process that lead to more aggressive forms of periodontitis.MAS

Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses

Bone Replacement Materials and Techniques Used for Achieving Vertical Alveolar Bone Augmentation

Alveolar bone augmentation in vertical dimension remains the holy grail of periodontal tissue engineering. Successful dental implant placement for restoration of edentulous sites depends on the quality and quantity of alveolar bone available in all spatial dimensions. There are several surgical techniques used alone or in combination with natural or synthetic graft materials to achieve vertical alveolar bone augmentation. While continuously improving surgical techniques combined with the use of auto- or allografts provide the most predictable clinical outcomes, their success often depends on the status of recipient tissues. The morbidity associated with donor sites for auto-grafts makes these techniques less appealing to both patients and clinicians. New developments in material sciences offer a range of synthetic replacements for natural grafts to address the shortcoming of a second surgical site and relatively high resorption rates. This narrative review focuses on existing techniques, natural tissues and synthetic biomaterials commonly used to achieve vertical bone height gain in order to successfully restore edentulous ridges with implant-supported prostheses

Quantitative Trait Loci and Candidate Genes for Neutrophil Recruitment in Sterile Inflammation Mapped in AXB-BXA Recombinant Inbred Mice

<div><p>Neutrophil recruitment (NR) to sites of sterile inflammation plays a key role in tissue damage and healing potential of lesions characteristic to non-infectious inflammatory diseases. Previous studies suggested significant genetic control of neutrophil survival, function, and migration in inflammatory responses to endogenous and exogenous stimuli. We have mapped the murine genome for quantitative trait loci (QTLs) harbouring genetic determinants that regulate NR in SI using a murine model of chemically-induced peritonitis. NR was quantified in 16 AXB-BXA recombinant inbred strains and their progenitors, A/J (A) and C57BL/6J (B). A continuous distribution of NR was found among the strains, with parent B showing higher NR and parent A showing lower NR (3.0-fold difference, p=0.05). Within the progeny strains, a 5.5-fold difference in NR was observed between the lowest, BXA1, and the highest responders AXB19 (p<0.001). This data was analyzed using GeneNetwork, which linked NR to one significant QTL on chromosome 12 (Peritoneal Neutrophil Recruitment 1, <i>PNR1</i>) and two suggestive QTLs (<i>PNR2</i>, <i>PNR3</i>) on chromosomes 12 and 16 respectively. Sixty-four candidate genes within <i>PNR1</i> were cross-referenced with currently published data, mRNA expression from two NR microarrays, and single nucleotide polymorphism analysis. The present study brings new light into the genetics of NR in response to cell injury and highlights potential candidate genes <i>Hif1α</i>, <i>Fntb</i>, and <i>Prkch</i> and their products for further studies on neutrophil infiltration and inflammation resolution in sterile inflammation.</p></div

Author Correction: ERV1 Overexpression in Myeloid Cells Protects against High Fat Diet Induced Obesity and Glucose Intolerance

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ERV1 Overexpression in Myeloid Cells Protects against High Fat Diet Induced Obesity and Glucose Intolerance

Non-resolving inflammation is a central pathologic component of obesity, insulin resistance, type 2 diabetes and associated morbidities. The resultant hyperglycemia is deleterious to the normal function of many organs and its control significantly improves survival and quality of life for patients with diabetes. Macrophages play critical roles in both onset and progression of obesity-associated insulin resistance. Here we show that systemic activation of inflammation resolution prevents from morbid obesity and hyperglycemia under dietary overload conditions. In gain-of-function studies using mice overexpressing the human resolvin E1 receptor (ERV1) in myeloid cells, monocyte phenotypic shifts to increased patrolling-to-inflammatory ratio controlled inflammation, reduced body weight gain and protected from hyperglycemia on high-fat diet. Administration of a natural ERV1 agonist, resolvin E1, recapitulated the pro-resolving actions gained by ERV1 overexpression. This protective metabolic impact is in part explained by systemic activation of resolution programs leading to increased synthesis of specialized pro-resolving mediators

Neutrophil recruitment variation in AXB-BXA RI and the parental mouse strains, A and B (n = 80, up to 6mice/strain).

<p>Hemocytometer cell count is expressed as mean number of neutrophil recruited ± SEM. This strain distribution panel shows a 3.0- fold recruitment variation between the 2 parental strains (p = 0.05) and 5.5-fold between the lowest and highest responders (p<0.001).</p