Endocrine, Metabolic & Immune Disorders-Drug Targets (Formerly Current Drug Targets - Immune, Endocrine & Metabolic Disorders) - Volume 10, Issue 2, 2010

Full text available

In this review, we discuss the genetic architecture of obesity and the metabolic syndrome, highlighting recent advances in identifying genetic variants and loci responsible for a portion of the variation in components of the metabolic syndrome, namely, adiposity traits, serum HDL and triglycerides, blood pressure, and glycemic traits. We focus particularly on recent progress from large-scale genome-wide association studies (GWAS), by detailing their successes and how lessons learned can pave the way for future discovery. Results from recent GWAS coalesce with earlier work suggesting numerous interconnections between obesity and the metabolic syndrome, developed through several potentially pleiotropic effects. We detail recent work by way of a case study on the cadherin 13 gene and its relation with adiponectin in the HyperGEN and the Framingham Heart Studies, and its association with obesity and the metabolic syndrome. We provide also a gene network analysis of recent variants related to obesity and metabolic syndrome discovered through genome- wide association studies, and 4 gene networks based on searching the NCBI database.

The metabolic syndrome represents a clustering of risk factors that has been shown to predict adverse cardiovascular outcomes. Although the precise mechanisms contributing to the cardiometabolic syndrome (CMS) remain poorly defined, accumulating evidence identifies two intersecting candidate pathways responsible for inflammation and energy homeostasis in the pathophysiology that underlie cardiometabolic traits. Although currently no pharmacologic interventions specifically target CMS, future drug development efforts should attempt to capitalize on molecular nodes at the intersections of these pathways in the CMS.

Given the higher burden of risk factors for metabolic syndrome (MetS) on morbidity and mortality, it is critical to prevent the development of metabolic syndrome in the first place. While dietary habits have been favorably associated with some of the factors included in the definition of metabolic syndrome, limited and inconsistent data have been reported on the role of nutrition in the development of metabolic syndrome. Currently, there is no consensus as to which dietary patterns would confer the lowest risk of MetS. Identification of dietary patterns, food groups, or nutrients that may lower the incidence of metabolic syndrome could improve prevention strategies as well as prognosis among subjects with existing MetS. This manuscript reviews current evidence on dietary patterns, consumption of fat, whole grains, carbohydrate quality and quantity, and moderate alcohol consumption as they relate to metabolic syndrome.

The fibric acid derivative, fenofibrate (FF) has been used in the US since 1998 to manage patients with dyslipidemia. Typical changes in serum lipids as a result of FF treatment include clinically important mean reductions of serum triglycerides (TG) by a mean change of -93.7 mg/dL (-39.3%), increases of high density lipoprotein cholesterol (HDLC) by +5.5 mg/dL (+12.4%), and reductions in low density lipoprotein cholesterol (LDLC) by -17.9 mg/dL (-12.3%). The greatest reductions in serum TG are usually observed in subjects with elevated baseline TG including those with the metabolic syndrome (MetS). Although statins remain the mainstay of therapy for most dyslipidemic patients, their combined use with FF would be expected to address residual risk resulting from less than optimal TG and HDLC levels in such patients. Clinical trials examining the cardiovascular benefits of FF alone or combined with statins have produced mixed results. These observations underscore our lack of understanding of which patients may benefit from FF therapy and which do not. Although FF's basic mechanism of action is known to involve PPAR-α agonist activity resulting in altered transcription of several genes, the actual genetic bases for variability in lipid response is poorly understood. Studies, such as our GOLDN study and others were designed to better understand the genetic determinants of variability in the response to FF treatment and lipid levels. As a result several important genetic determinants of lipid levels have been identified. For example, in the GOLDN study SNPs from different genes were significantly associated with baseline lipid levels before treatment (APOA5- rs662799, rs3135506; APOC3- rs5128, rs2854117, rs4520); APOA4- rs5104; PPARArs9626730, rs135543, rs11703495; LPL- rs1801177), after treatment PPARA- rs11708495; LPL- rs1801177, and appeared to modulate overall response to FF treatment (NOS3- rs1799983). In this article, we will review the literature leading up to the contemporary use of FF as an agent to manage patients with dyslipidemia and focus on emerging understanding of the genetic variability in response to FF treatment. On the basis of the available evidence, we conclude that FF is of benefit in the treatment of dyslipidemia, especially among those with MetS. However, more work is needed to specifically identify which individuals derive a benefit from FF administration in terms of clinical outcomes and which do not - particularly in the context of type 2 diabetes.

Atherosclerosis is an inflammatory disease characterized by lipid accumulation as well as vascular injury due to a massive infiltration of immune cells in the endothelial wall. Microbial and self- antigens are responsible for a persistent activation of immune and non-immune cells, thus leading to a condition of arterial chronic inflammation with plaque formation and rupture in complicated cases. In particular, the effects of bacteria, viruses and their toxic products as well as of glycated lipoproteins will be illustrated with special reference to the main inflammatory pathways triggered by a persistent antigenic load in the host. Taking into consideration this broad variety of antigens implicated in the pathogenesis of atherosclerosis, therapeutic approaches such as antibiotics, dietary intervention and immune therapies will be discussed.

Interferon-beta (IFNβ) has been used over the past 15 years as a first-line therapy for relapsing remitting multiple sclerosis (RR MS), however its mechanisms of action are still not completely elucidated. Recently discovered Th17 cells have been hypothesized to play a crucial role in the development of autoimmune diseases, including MS. Studies from our laboratory and others have demonstrated that IFNβ treatment suppresses Th17 cells' differentiation, mediated by its effects on dendritic cells (DCs), B-cells and T-cells. IFNβ induces the production of the Th17-suppressive cytokines interleukin (IL)-27 and IL-12 in DCs and B-cells through the phosphorylation of signal transducers and activators of the transcription protein (STAT)1. Its inhibition of the Th17-promoting cytokines IL-1β and IL-23 is mediated via induction of suppressor of cytokine signaling (SOCS)3 expression. In naive CD45RA+ T-cells, IFNβ directly suppresses Th17 cells' differentiation, as evidenced by the suppression of this cell subset's specific transcription factor retinoic acid-related orphan receptor (ROR)c, cytokine IL-17A and the surface markers chemokine receptor (CCR)6 and IL-23R. The IFNβ-mediated induction of IL-10 in T-cells and B-cells represents an important additional immunoregulatory mechanism. Described IFNβ's mechanisms of action selectively target Th17 cell-mediated autoimmune responses in patients with RR MS.

WNT4 signaling pathways represent an important step in the multi-faceted process of mammalian gonadal differentiation and the development of internal genitalia. WNT4 protein controls the cytoplasmatic stability of specific transcriptional coactivator β catenin during both embriogenesis and adult homeostasis. The biological significance of WNT4 consists in determining the final female reproductive system, inhibiting Wolff ducts' differentiation, male steroidogenesis and vascular cell migration. An overview of WNT4 cellular mechanisms is given in order to understand its critical role in the genesis of various human diseases such as congenital malformations and gynecological disorders like polycystic ovary syndrome (PCOS). The final discussion focusses on several possible therapeutic uses of Wnt4 both during pregnancy in order to correct the genetic loss of function of the protein and during adulthood in order to normalize fertility in PCOS-affected females planning pregnancy.

Preterm infants may pass meconium only after the first 48 hours of life, even in the absence of any gastrointestinal disease. The role of various factors in determining the time of meconium elimination has been recently assessed. Gestational age and start of feeding had been demonstrated to influence first meconium timing. The aim of our study was to evaluate the time of first meconium passage and the time to achieve regular bowel movements (RBM), correlating these two events to different factors such as gestational age (GA), sex, type of delivery [caesarean section (CS) vs spontaneous delivery (SD)], 1' and 5' Apgar score (1'AS, 5'AS), time and type of feeding, oxygen requirement and any mode of respiratory support.

The world population, currently estimated to be over six billions, is expected to double in the next forty years. The projected growth will cause severe over crowding that will have an adverse effect on the ecological health of the planet. A recent survey by the United Nations found that a majority of men in many countries are willing to participate in family planning by taking full control of their fertility. However, the available contraceptives for men have either higher failure rates or they are irreversible. Thus, the contraceptive needs of tens of millions of men go unmet every day resulting in millions of unwanted pregnancies, and hundreds of thousands of abortions. Since the introduction of oral contraceptive (pill) for women over five decades ago, there have been numerous collaborative efforts by scientists and pharmaceutical companies to improve the effectiveness and delivery of contraceptives to women who wish to safely regulate their reproductive physiology. However, the contraceptive options available to men have not changed in several decades and are still limited to the use of condoms and timely withdrawal (coitus interruptus) or under going a minor surgical procedure (vasectomy) that prevents the release of spermatozoa during ejaculation. The first two methods have relatively higher typical-use failure rates, whereas the last approach is largely irreversible and not suitable for younger men. Despite nonstop efforts worldwide, we may still be several years away from providing safe, effective and affordable male contraceptives which will allow both men and women to participate fully in family planning. In this article, we will discuss various contraceptives currently available to regulate male fertility. In addition, we will summarize potentially new contraceptives for men that are at various stages of research and development. Finally, our intention is to discuss details of two safe, reversible and affordable male contraceptive approaches that are inching closure to being approved for use by the masses in India and China, the world's two most populous nations.