Recurrent glucose deprivation leads to the preferential use of lactate by neurons in the ventromedial hypothalamus.

Increased GABAergic output in the ventromedial hypothalamus (VMH) contributes to counterregulatory failure in recurrently hypoglycemic (RH) rats, and lactate, an alternate fuel source in the brain, contributes to this phenomenon. The current study assessed whether recurring bouts of glucose deprivation enhanced neuronal lactate uptake and, if so, whether this influenced γ-aminobutyric acid (GABA) output and the counterregulatory responses. Glucose deprivation was induced using 5-thioglucose (5TG). Control rats received an infusion of artificial extracellular fluid. These groups were compared with RH animals. Subsequently, the rats underwent a hypoglycemic clamp with microdialysis. To test whether 5TG affected neuronal lactate utilization, a subgroup of 5TG-treated rats was microinjected with a lactate transporter inhibitor [cyano-4-hydroxycinnamate (4CIN)] just before the start of the clamp. Both RH and 5TG raised VMH GABA levels, and this was associated with impaired counterregulatory responses. 4CIN reduced VMH GABA levels and restored the hormone responses in the 5TG group. We then evaluated [14C]lactate uptake in hypothalamic neuronal cultures. Recurring exposure to low glucose increased monocarboxylate transporter-2 mRNA expression and augmented lactate uptake. Taken together, our data suggest that glucose deprivation, per se, enhances lactate utilization in hypothalamic neurons, and this may contribute to suppression of the counterregulatory responses to hypoglycemia.

HELLP Syndrome: Pathophysiology and Current Therapies.

HELLP syndrome is a disorder associated with serious maternal morbidity and mortality. Distinguishing HELLP from other pregnancy-related disorders is often challenging and may result in delay of treatment. Differential diagnoses include acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, antiphospholipid syndrome, and hemolytic uremic syndrome, and are reviewed in this chapter. While there is not any current treatment for HELLP, the mainstay of treatment involves maternal stabilization and timely delivery. Various treatment strategies have been attempted to help decrease the morbidity and mortality of HELLP, including the maternal use of corticosteroids. The authors review the studies and controversies surrounding the maternal use of corticosteroids, plasma exchange, and low molecular weight heparin for the treatment of HELLP, as well as the role of the complement system in HELLP. Further large, well-designed, randomized controlled trials are needed to address the role corticosteroids may play in the treatment of women with HELLP and to help improve maternal and fetal outcomes.

Localized delivery of interferon-ß by Lactobacillus exacerbates experimental colitis.

BACKGROUND: There have been conflicting reports of the role of Type I interferons (IFN) in inflammatory bowel disease (IBD). Clinical trials have shown potent efficacy of systemic interferon-beta (IFN-ß) in inducing remission of ulcerative colitis. Likewise, IFNAR1(-/-) mice display an increased sensitivity to dextran sulfate sodium (DSS)-induced colitis, suggesting Type I IFN play a protective role during inflammation of the gut. Curiously, however, there have also been reports detailing the spontaneous development of IBD in patients receiving systemic IFN-ß therapy for multiple sclerosis or hepatitis. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the effects of local administration of IFN-ß on a murine model of colitis, we developed a transgenic Lactobacillus acidophilus strain that constitutively expresses IFN-ß (La-IFN-ß). While pretreatment of mice with control Lactobacillus (La-EV) provided slight protective benefits, La-IFN-ß increased sensitivity to DSS. Analysis showed colitic mice pretreated with La-IFN-ß had increased production of TNF-α, IFN-γ, IL-17A and IL-13 by intestinal tissues and decreased regulatory T cells (Tregs) in their small intestine. Examination of CD103(+) dendritic cells (DCs) in the Peyer's patches revealed that IFNAR1 expression was dramatically reduced by La-IFN-ß. Similarly, bone marrow-derived DCs matured with La-IFN-ß experienced a 3-fold reduction of IFNAR1 and were impaired in their ability to induce Tregs. CONCLUSIONS/SIGNIFICANCE: Our IFNAR1 expression data identifies a correlation between the loss/downregulation of IFNAR1 on DCs and exacerbation of colitis. Our data show that Lactobacillus secreting IFN-ß has an immunological effect that in our model results in the exacerbation of colitis. This study underscores that the selection of therapeutics delivered by a bacterial vehicle must take into consideration the simultaneous effects of the vehicle itself.