Athletic, muscular and hormonal evaluation in CrossFit® athletes using the “Elevation Training Mask”

Introduction: The possibility of performing intense workouts without falling into states of chronic fatigue stimulates the use of devices that improve muscular and hormonal functionality in athletes. The Elevation Training Mask (Training Mask LLC) (ETM) allows the application of hypoxia during exercise. The ETM is integrated into training routines increasing the physical stimulus to improve performance. Objective: We evaluated the impact of ETM on Workouts of the Day (WODs), muscular and hormonal behavior in Crossfit® athletes. Material and method: Prospective cohort study. During 12 weeks 20 Crossfit® athletes trained 60 minutes 3 days a week were randomly divided into 2 groups, control group (CG) (n=10) and ETM group (EG) (n=10) applying an additional progressive simulated altitude between 914 and 2743 meters. WODs (press, squat, deadlift, total CF and grace), macular markers: lactate dehydrogenase (LDH); creatine kinase (CK); myoglobin (Mb) and hormones: testosterone (T); cortisol (C), were evaluated at 2 time points of the study: day 1 (T1) and day 84 (T2). Results: All WODs and parameters LDH, CK, Mb, T and C showed no significant difference (p>0.05) in the time group interaction. In EG, a substantially lower percentage change (Δ) between T1 and T2 was observed in Mb (-16.01±25.82%), CK (6.16±26.05%) and C (-0.18±4.01%) than in CG (Mb: -094±4.39%; CK: 17.98±27.19%; C: 4.56±3.44%). The Δ T1-T2 in the WODs were similar. Conclusion: After 12 weeks of training under simulated hypoxia conditions with ETM there are no improvements in athletic performance assessed by WODs. However, the greater tendency to decrease Mb, CK and C, after using ETM, could stimulate recovery and indicate a lower muscle catabolism of the Crossfit® athlete in the long term.

Exogenously Applied Spermidine Alleviates Hypoxia Stress in Phyllostachys Praecox Seedlings Via Changes in Endogenous Hormones and Gene Expression

PurposeHypoxia stress is thought to be one of the major abiotic stresses that inhibits the growth and development of higher plants. Phyllostachys pracecox is sensitive to oxygen and suffers soil hypoxia during cultivation; however, the corresponding measures to mitigate this stress are still limited in practice. In this study, a simulated hypoxia stress with flooding was conducted to investigate the regulatory effect of Spermidine (Spd) on P. praecox seedlings. MethodsIndicators including growth, membrane lipid peroxidation, S-adenosylmethionine decarboxylase (SAMDC), ACC oxidase (ACO) and ACC synthetase (ACS) activities, indole-3-acetic acid (IAA) and abscisic acid (ABA) content, and expression of hormone-related genes in P. praecox were measured. ResultsApplication of 1 mM and 2 mM Spd could alleviate plant growth inhibition and reduce oxidative damage from hypoxia stress. Exogenous Spd significantly (P<0.05) increased SAMDC activity, enhanced ABA and IAA content, and reduced ACO and ACS activities to protect membranes from lipid peroxidation. Moreover, exogenous Spd up-regulated the expression of auxin-related genes auxin responsive factor1 (ARF1), auxin1 protein (AUX1), auxin2 protein (AUX2), auxin3 protein (AUX3) and auxin4 protein (AUX4), and down-regulated the expression of ethylene-related ACO and ACS genes during flooding. ConclusionThe results indicated that exogenous Spd altered hormone concentrations and the expression of hormone-related genes, thereby protecting the bamboo growth. Our data suggest that Spd can be used to reduce hypoxia-induced cell damage and improve the adaptability of P. praecox to flooding stress.

Butyrate Protects Porcine Colon Epithelium from Hypoxia-Induced Damage on a Functional Level

The large intestinal epithelium is confronted with the necessity to adapt quickly to varying levels of oxygenation. In contrast to other tissues, it meets this requirement successfully and remains unharmed during (limited) hypoxic periods. The large intestine is also the site of bacterial fermentation producing short-chain fatty acids (SCFA). Amongst these SCFA, butyrate has been reported to ameliorate many pathological conditions. Thus, we hypothesized that butyrate protects the colonocytes from hypoxic damage. We used isolated porcine colon epithelium mounted in Ussing chambers, incubated it with or without butyrate and simulated hypoxia by changing the gassing regime to test this hypothesis. We found an increase in transepithelial conductance and a decrease in short-circuit current across the epithelia when simulating hypoxia for more than 30 min. Incubation with 50 mM butyrate significantly ameliorated these changes to the epithelial integrity. In order to characterize the protective mechanism, we compared the effects of butyrate to those of iso-butyrate and propionate. These two SCFAs exerted similar effects to butyrate. Therefore, we propose that the protective effect of butyrate on colon epithelium under hypoxia is not (only) based on its nutritive function, but rather on the intracellular signaling effects of SCFA.

Hypoxia–CXCL6 axis affects arteriolar niche remodeling in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant clonal disease derived from hematopoietic stem/progenitor cell. Leukemia blasts cause extensive hypoxia of bone marrow (BM), which lead to disorder and remodeling of BM niche, thereby becoming “leukemic niche” to support the development and drug-resistance of AML as well as the maintenance of normal hematopoietic stem cells. In this study, the biological characteristics (such as self-renewal, apoptosis, migration, autocrine) and function (vascularization) of mesenchymal stem cells (MSCs) and human umbilical artery endothelial cells (HUAECs) that make up BM arteriolar niche in simulated hypoxia AML context were investigated. It was found that moderate hypoxia enhanced the viability of the arteriolar niche cells, but severe hypoxia of AML BM resulted in the damage of arteriolar niche cells and the disorder of vascular cytokines C-X-C motif chemokine ligand 6 (CXCL6). The dynamic changes of CXCL6 in the system as well as its anti-apoptotic and promoting angiogenic effects suggested that CXCL6 played an important role in the remodeling of BM arteriolar niche in AML. Taking advantage of CXCL6 can save the damaged MSCs and HUAECs, which is the hope of rescuing arteriolar niche. It is suggested that CXCL6 may be an assistant strategy for microenvironment targeted therapy of AML.

Abstract 257: Calreticulin Regulates Acetylation in Cardiac Cells During Endoplasmic Reticulum Stress

Background: Myocardial infarction (MI) is exacerbated by endoplasmic reticulum (ER) stress, which contributes to apoptosis signaling and tissue death in cardiomyocytes. Although the calcium-handing protein calreticulin is upregulated during MI, the role of calreticulin in the progression of ER stress remains controversial. We hypothesized that calreticulin expression accelerates ER stress via regulation of the acetylation status of ER proteins, and knockdown reduces pro-apoptotic ER stress. Methods: We examined the expression of calreticulin in human cardiac cells in response to ischemia or thapsigargin-mediated ER stress. To test the effect of calreticulin modulation on cell mortality, we generated a stable partial calreticulin knockdown line in proliferating human cardiomyocyte-derived cells. We further examined the induction and acetylation of ER stress signaling proteins, including proteins in each of the three major pathways that account for ER-stress mediated cell death. Results and Conclusions: Calreticulin is upregulated in human ischemic heart failure cardiac tissue, as well as simulated hypoxia and reoxygenation and thapsigargin-mediated ER stress. It was found that partial knockdown protects against the expression of caspase 12, CHOP, and reduces thapsigargin-driven TUNEL staining. In addition, significant changes in the acetylation of ER stress proteins and the expression of the deacetylase SIRT1 were observed. These data shed light on the role that calreticulin plays in apoptosis signaling during ER stress in cardiac cells.

Inhibition of Migration and Invasion of Hepatocarcinoma HepG2 Cells by Dietary Saponins via Targeting HIF-1α

Background: Different saponins from herbs have been used as tonic or functional foods, and for treatment of various diseases including cancers. Although clinical data has supported the function of these saponins, their underlying molecular mechanisms have not been well defined. Methods: With the simulated hypoxia created by 8 hours of Cu++ exposure and following 24 hour incubation with different concentration of saponins in HepG2 cells for MTT assay, migration and invasion assays, and for RT-PCR, and with each group of cells for immunofluorescence observation by confocal microscopy. Results： ZC-4 had the highest rate of inhibition of cell proliferation by MTT assay, and the highest inhibition of migration rate by in vitro scratch assay, while ZC-3 had the highest inhibition of invasion ratio by transwell assay. Under the same simulated hypoxia, the molecular mechanism of saponin function was conducted by measuring the gene expression of Hypoxia Inducible Factor (HIF)-1α through RT-PCR, in which ZC-3 showed a potent inhibition of gene HIF-1α. For the protein expression by immunofluorescence staining with confocal microscopy, HIF-1α was also inhibited by saponins, with the most potent one being ZC-4 after eight hours’ relatively hypoxia incubation. Conclusion: Saponins ZC-4 and ZC-3 have the potential to reduce HepG2 cell proliferation, migration and invasion caused by hypoxia through effectively inhibiting the gene and protein expression of HIF-1α directly and as antioxidant indirectly