Immune dysfunction in developmental programming of type 2 diabetes mellitus.

Intrauterine growth restriction (IUGR) is a common complication of pregnancy and increases the risk of the offspring developing type 2 diabetes mellitus (T2DM) later in life. Alterations in the immune system are implicated in the pathogenesis of IUGR-induced T2DM. The development of the fetal immune system is a delicate balance as it must remain tolerant of maternal antigens whilst also preparing for the post-birth environment. In addition, the fetal immune system is susceptible to an altered intrauterine milieu caused by maternal and placental inflammatory mediators or secondary to nutrient and oxygen deprivation. Pancreatic-resident macrophages populate the pancreas during fetal development, and their phenotype is dynamic through the neonatal period. Furthermore, macrophages in the islets are instrumental in islet development as they influence ß-cell proliferation and islet neogenesis. In addition, cytokines, derived from ß-cells and macrophages, are important to islet homeostasis in the fetus and adult and, when perturbed, can cause islet dysfunction. Several activated immune pathways have been identified in the islets of people who experienced IUGR, with alternations in the levels of IL-1ß and IL-4 as well as changes in TGFß signalling. Leptin levels are also altered. Immunomodulation has shown therapeutic benefit in T2DM and might be particularly useful in IUGR-induced T2DM.

The Severity of Neurological Dysfunction in Preschool Children, Secondary to Damage Generated During the Perinatal Period, is Associated With a Pro-Inflammatory Pattern of Serum Molecules.

Disorders in the child's neurological development caused by perinatal risks can lead to long-term altered neurological signs that begin at an early age and involve persistent functional disorders. Recent data suggest that tissue dysfunction, not just acute damage, may initiate or perpetuate an inflammatory response. The aim of this study was to find out if any neurological dysfunction in preschool children secondary to damage generated during the perinatal period is associated with the magnitude of perinatal risks and long-term modifications in the serum concentrations of inflammatory molecules. The participants, aged 1-4 years, were on neurodevelopmental follow-up and rehabilitation therapy from the first three months of life and had no acute disease data. We classified the children into three groups according to the importance of their perinatal risks: low, medium, and high. The results show that 1) the magnitude of perinatal risks correlated with the severity of neurological dysfunction; 2) the greatest changes in the concentrations of the molecules of the inflammatory process were associated with the most altered neurological signs. This suggests that persistent nervous system dysfunction keeps inflammatory responses active even in the absence of an acute process of infection or damage.

Lipopolysaccharide-Induced Preconditioning Attenuates Apoptosis and Differentially Regulates TLR4 and TLR7 Gene Expression after Ischemia in the Preterm Ovine Fetal Brain.

Acute exposure to subclinical infection modulates subsequent hypoxia-ischemia (HI) injury in a time-dependent manner, likely by cross-talk through Toll-like receptors (TLRs), but the specific pathways are unclear in the preterm-equivalent brain. In the present study, we tested the hypothesis that repeated low-dose exposure to lipopolysaccharide (LPS) before acute ischemia would be associated with induction of specific TLRs that are potentially neuroprotective. Fetal sheep at 0.65 gestation (term is ∼145 days) received intravenous boluses of low-dose LPS for 5 days (day 1, 50 ng/kg; days 2-5, 100 ng/kg) or the same volume of saline. Either 4 or 24 h after the last bolus of LPS, complete carotid occlusion was induced for 22 min. Five days after LPS, brains were collected. Pretreatment with LPS for 5 days decreased cellular apoptosis, microglial activation and reactive astrogliosis in response to HI injury induced 24 but not 4 h after the last dose of LPS. This was associated with upregulation of TLR4, TLR7 and IFN-ß mRNA, and increased fetal plasma IFN-ß concentrations. The association of reduced white matter apoptosis and astrogliosis after repeated low-dose LPS finishing 24 h but not 4 h before cerebral ischemia, with central and peripheral induction of IFN-ß, suggests the possibility that IFN-ß may be an important mediator of endogenous neuroprotection in the developing brain.

The four most common pediatric immunodeficiencies.

The four most common immunodeficiencies in pediatric patients are transient hypogamma-globulinemia of infancy, IgG subclass deficiency, impaired polysaccharide responsiveness (partial antibody deficiency) and selective IgA deficiency. Most of these patients have normal cellular immune systems, phagocyte function and complement levels. All four illnesses are characterized by recurrent bacterial respiratory infections such as purulent rhinitis, sinusitis, otitis and bronchitis. Except for some IgA-deficient patients, the molecular basis for these illnesses is not known, and indeed each syndrome is heterogeneous, with multiple causes, including genetic factors, drug/environmental toxicant exposure, and/or prenatal physiological events. This paper describes the clinical and laboratory features, postulated causes, current management and prognosis. Only a few of these cases require the use of intravenous IgG (IVIG) and the outlook for long life is excellent.

Regenerative healing in fetal skin: a review of the literature.

In mature skin, wound repair typically begins with hemostasis and inflammation. This is followed by a proliferative phase with reepithelialization, angiogenesis, and collagen production, and ends with the generation of a permanent scar. However, animal studies and clinical observations have shown that a different type of healing occurs in fetal skin in the first two trimesters of development. In early fetal skin, wounds exhibit a unique pattern of wound healing leading to regeneration. Notably, repair in the fetus takes place with little or no inflammation, faster reepithelialization, and no scarring. Although research in scarless fetal healing began several decades ago, the exact mechanisms of how this regenerative process takes place remain unknown. Knowing how the fetus will respond to potential injury from invasive diagnostic procedures or surgery is essential, especially given the development of less invasive fetal surgical techniques which could increase the number of fetal surgeries. In addition, insights into regenerative healing may provide information about how to accelerate postnatal wound healing as well as how to improve healing from a cosmetic standpoint. Future research directions include identification of the molecular controls responsible for scarless healing, with the intention that this new information will lead to improved therapeutic strategies for wound healing.

Tissue factor: a link between C5a and neutrophil activation in antiphospholipid antibody induced fetal injury.

Fetal loss in patients with antiphospholipid (aPL) antibodies has been ascribed to thrombosis of placental vessels. However, we have shown that inflammation, specifically activation of complement with generation of the anaphylotoxin C5a, is an essential trigger of fetal injury. In this study, we analyzed the role of the procoagulant molecule tissue factor (TF) in a mouse model of aPL antibody-induced pregnancy loss. We found that either blockade of TF with a monoclonal antibody in wild-type mice or a genetic reduction of TF prevented aPL antibody-induced inflammation and pregnancy loss. In response to aPL antibody-generated C5a, neutrophils express TF potentiating inflammation in the deciduas and leading to miscarriages. Importantly, we showed that TF in myeloid cells but not fetal-derived cells (trophoblasts) was associated with fetal injury, suggesting that the site for pathologic TF expression is neutrophils. We found that TF expression in neutrophils contributes to respiratory burst and subsequent trophoblast injury and pregnancy loss induced by aPL antibodies. The identification of TF as an important mediator of C5a-induced oxidative burst in neutrophils in aPL-induced fetal injury provides a new target for therapy to prevent pregnancy loss in the antiphospholipid syndrome.

Mononuclear phagocyte system in mice with intrauterine Candida albicans infection and postnatal experimental tuberculosis.

Intrauterine Candida albicans infection in mouse fetuses affected the type of granulomatous inflammation induced by BCG vaccine during the postnatal period. It manifested in increased formation of granulomas and variations in their cellular composition.