A novel acute anemia model for pharmacological research in mice by compelled acute exercise

Three-dimensional imaging and analysis of pathological tissue samples with de novo generation of citrate-based fluorophores

Two-dimensional (2D) histopathology based on the observation of thin tissue slides is the current paradigm in diagnosis and prognosis. However, labeling strategies in conventional histopathology are limited in compatibility with 3D imaging combined with tissue clearing techniques. Here, we present a rapid and efficient volumetric imaging technique of pathological tissues called 3D tissue imaging through de novo formation of fluorophores, or 3DNFC, which is the integration of citrate-based fluorogenic reaction DNFC and tissue clearing techniques. 3DNFC markedly increases the fluorescence intensity of tissues by generating fluorophores on nonfluorescent amino-terminal cysteine and visualizes the 3D structure of the tissues to provide their anatomical morphology and volumetric information. Furthermore, the application of 3DNFC to pathological tissue achieves the 3D reconstruction for the unbiased analysis of diverse features of the disorders in their natural context. We suggest that 3DNFC is a promising volumetric imaging method for the prognosis and diagnosis of pathological tissues.

Inorganic Iron Supplementation Rescues Hematological Insufficiency Even Under Intense Exercise Training in a Mouse Model of Iron Deficiency with Anemia

Iron deficiency anemia (IDA) due to malnutrition and/or blood loss is a common condition, especially in women of reproductive age. Intense exercise can induce anemia via an inflammatory response, but whether intense exercise affects the efficacy of iron supplementation to treat IDA is unclear. Here, we show in a mouse model of IDA that acute intense swimming increased IL-6 levels in the blood, but did not affect the maximum elevation of plasma iron following oral administration of 0.5 mg/kg Bw iron. However, compared with the control group without intense exercise, acute intense swimming was associated with a significant decrease in plasma iron 2 and 4 h after iron loading that could be attributed to rapid iron absorption in peripheral tissues. In the chronic experiment, IDA mice administered 0.36, 1.06, or 3.2 mg/kg Bw iron per day that were subjected to 11 intense swimming sessions over 3 weeks showed significantly decreased recovery levels for hemoglobin and red blood cell count during the early phase of the experimental period. At the end of the experimental period, significant, dose-dependent effects of iron, but not the main effect of intense exercise, were seen for recovery of hemoglobin and red blood cell counts, consistent with the acute exercise study. These results suggested that intense exercise in the presence of IDA does not inhibit iron absorption from the gastrointestinal tract and that iron supplementation can enhance the recovery process even after intense exercise.

The role of inflammatory cytokines in anemia and gastrointestinal mucosal injury induced by foot electric stimulation

Foot electrical stimulation (FES) has been considered as a classic stressor that can disturb homeostasis. Acute anemia was observed in the model induced by FES. The aim of this study was to explore the role of inflammatory cytokines underlying the acute anemia and gastrointestinal (GI) mucosal injury in the FES. Twenty-four male Kunming mice (20 ± 2 g) were randomly divided into control group and experimental group. The mice were placed in a footshock chamber that can generate 0.5 mA electrical impulse periodically for 0.5 h. After the process, red blood cell count, hemoglobin concentration and hematocrit, the levels of corticotropin releasing hormone (CRH) in serum and hypothalamus, and adrenocorticotropic hormone (ACTH) in serum and pituitary were detected separately. In addition, we investigated the expressions of inflammatory cytokines (IL-1, IL-6, TNF-α, iNOS, and IL-10) in the hypothalamus and duodenum by Polymerase Chain Reaction (PCR). Results showed that this FES model induced anemia, increased CRH and ACTH activity in the serum after the FES. Moreover, the expressions of IL-1β, IL-6, TNF-α, and iNOS were significantly increased following the process, while IL-10 was not activated. These findings suggest that anemia, the inflammatory cytokines in the hypothalamus and duodenum of the mice in the model induced by FES is closely related to GI mucosal injury/bleeding. Taken together, these results underscore the importance of anemia, GI mucosal injury/bleeding and stress, future studies would be needed to translate these findings into the benefit of affected patients.

Red Blood Cell Function and Dysfunction: Redox Regulation, Nitric Oxide Metabolism, Anemia

SIGNIFICANCE

Recent clinical evidence identified anemia to be correlated with severe complications of cardiovascular disease (CVD) such as bleeding, thromboembolic events, stroke, hypertension, arrhythmias, and inflammation, particularly in elderly patients. The underlying mechanisms of these complications are largely unidentified. Recent Advances: Previously, red blood cells (RBCs) were considered exclusively as transporters of oxygen and nutrients to the tissues. More recent experimental evidence indicates that RBCs are important interorgan communication systems with additional functions, including participation in control of systemic nitric oxide metabolism, redox regulation, blood rheology, and viscosity. In this article, we aim to revise and discuss the potential impact of these noncanonical functions of RBCs and their dysfunction in the cardiovascular system and in anemia.

CRITICAL ISSUES

The mechanistic links between changes of RBC functional properties and cardiovascular complications related to anemia have not been untangled so far.

FUTURE DIRECTIONS

To allow a better understanding of the complications associated with anemia in CVD, basic and translational science studies should be focused on identifying the role of noncanonical functions of RBCs in the cardiovascular system and on defining intrinsic and/or systemic dysfunction of RBCs in anemia and its relationship to CVD both in animal models and clinical settings. Antioxid. Redox Signal. 26, 718-742.