ECSS Paris 2023: OP-PN13
INTRODUCTION: Physical exercise, particularly high-intensity interval exercise (HIIE), has demonstrated anti-tumor effects, partly through the release of myokines—proteins secreted during muscle contraction that facilitate inter-organ communication and regulate essential biological processes. Previous studies have shown that HIIE-conditioned human serum (HIIE-HS) can reduce the viability and proliferation of breast cancer cells. However, the precise molecular mechanisms underlying these effects remain unclear, highlighting the need to investigate the impact of HIIE-conditioned serum exposure. Therefore, this study examines the mechanisms by which MCF-7 and MDA-MB-231 breast cancer cell lines respond to human serum collected before and after HIIE, focusing on cell viability, apoptosis, transcriptome analysis, and key signaling pathways involved in tumor progression. METHODS: MCF-7 and MDA-MB-231 breast cancer cells were incubated with human serum for 48 hours. Subsequently, cell viability was assessed using the MTT assay, while Western blot analyses targeted components of the Akt/mTOR pathway, apoptosis markers, and inflammation-related proteins. Apoptosis was further evaluated by flow cytometry using Annexin V and propidium iodide staining to distinguish early and late apoptotic cells. RNA sequencing was performed to assess transcriptional alterations induced by HIIE-HS, focusing on proliferation, cell cycle regulation, apoptosis, cell adhesion, and other key biological processes. RESULTS: The main findings indicate a decrease in 4EBP1 phosphorylation, with trends observed in Akt and P70S6K1. Additionally, increases in pro-caspase 9 and pro-caspase 3 were detected. However, cleaved caspase-3 was not observed, suggesting potential apoptosis resistance, which was confirmed by flow cytometry. Modifications were also observed in inflammation-related proteins such as MyD88 and NF-κB. RNA-seq analysis revealed an upregulation of apoptosis-related genes (e.g., TIPUH1) and negative regulators of cell proliferation (e.g., AZGP1), among others. CONCLUSION: These findings highlight the molecular mechanisms through which HIIE-HS impacts breast cancer cells, enhancing the understanding of how physical exercise affects tumor progression. This evidence reinforces the need for further research into the therapeutic potential of physical exercise as an adjuvant strategy in breast cancer treatment.
Read CV Mayalen Valero BretonECSS Paris 2023: OP-PN13
INTRODUCTION: In several studies, moderately elevated unconjugated bilirubin levels (UCB), as observed in Gilbert’s syndrome (GS), have been associated with a lower risk for cardio-vascular diseases. People with GS have been frequently described to have lower blood lipids. Furthermore, bilirubin is known to be a potent antioxidant in the human metabolism. Some studies also indicated that elite athletes show higher UCB levels than non-athletes. Considering all these observations it seemed interesting to look closer at the effect of acute exercise on blood lipid levels and some oxidative stress parameters in response to a graded cycle ergometer test in GS subjects and healthy controls. METHODS: In a human case control study, where controls were age and gender matched, 40 GS subjects (UCB>17.1μmol/l) and 40 controls (C) between 18 and 65 years of age were included. All participants were healthy, moderately physically active and nonsmokers. After having fasted for 12 h overnight, all subjects completed a graded exercise test on a cycle ergometer, which was terminated at RER=1.00. Before and after the test venous blood samples were taken. Total (TC) and HDL cholesterol, as well as triglycerides were measured and LDL cholesterol was calculated with the Friedewald equation by a certified laboratory. UCB was measured via high performance liquid chromatography (HPLC). For oxidative stress parameters, photometric methods were used for the measurements of the ratio of reduced to oxidized glutathione (GSH:GSSG) and FRAP (ferric reducing antioxidant power). DNA-damage was assed using the comet assay. RESULTS: At baseline, GS subjects (86.68 ± 20.234) had significantly (p=0.041) lower levels of LDL than C (96.23 ± 20.871). The rise in TC during exercise was significantly higher in C subjects (p=0.027). UCB levels rose significantly higher in GS subjects (p<0.001). Regarding oxidative stress parameters, the increase in the GSH:GSSG ratio was higher in C by trend (p=0.081). No difference between groups was observed in the other oxidative stress parameters, however all FRAP, GSH and GSSG increased in all groups, whereas DNA-damage decreased. When dividing into two age groups (cut-off 35 years) GS subjects in the older group had significantly lower LDL levels and a lower TC:HDL ratio as well as a lower LDL:HDL ratio (all p<0.05), whereas in younger subjects there was no significant difference at baseline. However, in younger subjects GSH levels were significantly higher in C subjects (p=0.037). CONCLUSION: This study again shows that the effect of bilirubin and it´s metabolism on blood lipid levels becomes more important with age. Furthermore, it seems that the graded exercise test had no impact on blood lipid levels, blood glucose or oxidative stress parameters. UCB levels seem to have no impact on the influence of exercise on the analyzed parameters. However, it is interesting that bilirubin metabolism of GS subjects seems to be more triggered by exercise compared to the normo-bilirubinemic controls.
Read CV Tamara StelzerECSS Paris 2023: OP-PN13
INTRODUCTION: Carnosine (ß-alanyl-l-histidine) is a dipeptide with important biological functions abundantly expressed in excitable tissues such as the nervous system and the skeletal muscle. Carnosine has anti-inflammatory, antioxidant, anti-glycation and reactive carbonyl-quenching properties. However, the functions played by endogenous carnosine remain poorly understood in the literature. We investigated the impact of carnosine absence on oxidative stress induced by an acute physical exercise session (PE), and by an experimental chronic kidney disease model (5/6 Nx), in CARNS1 knockout rats (KO) and wild-type controls (WT). METHODS: 64 male 4 months-old wistar rats were used in two sub-studies: the PE study (WT Exercise: n=8, KO Exercise: n=8, WT Control: n=8, KO Control: n=8) and the 5/6 Nx study (WT Sham: n=8, KO Sham: n=8, WT 5/6 Nx: n=8, KO 5/6 Nx: n=8). The exercise protocol consisted of an acute 90-minute swimming session with a 3% body weight load attached to the tail. Kidney disease was induced by 5/6 nephrectomy, i.e., a full nephrectomy of the right kidney followed by the ligation of two branches of the left renal artery. The sham surgey served as a control. In the PE study, oxidative stress markers including superoxide dismutase (SOD) and catalase (CAT) activity, thiobarbituric acid reactive substances (TBARS), and protein carbonyl content were analyzed in the soleus muscle. In the 5/6 Nx study, these parameters were measured in kidney tissue, and GFR was assessed via inulin clearance (Cin). An one-way ANOVA was performed to compare groups and Mann-Whitney was used to assess GFR differences between WT and KO. All data are expressed as mean ± SD. RESULTS: In the PE study, acute PE did not alter CAT, SOD, or TBARS concentrations but it increases protein carbonyl content, with no differences being observed between genotypes in the soleus muscle. The absence of carnosine led to a significant increase in TBARS levels after exercise in the KO control group compared to the WT control group (23.34±5.84 vs. 11.64±3.50 nmol MDA/mg protein respectively, p=0.0003). In the 5/6 Nx study, KO 5/6 Nx exhibited significantly higher SOD activity compared to WT 5/6 Nx (45.89±16.63 vs. 20.57±8.88 U/mg protein respectively, p=0.0019) and increased protein carbonyl content (1.87±0.09 vs. 1.66±0.13 mmol carbonyl/mg protein respectively, p=0.0079). A similar response was observed in KO sham vs. WT sham (1.74±0.09 vs. 1.51±0.14 respectively, p=0.0039). We found no diferences between genotypes in kidney TBARS concentrations. TBARS levels in plasma were significantly elevated in KO 5/6 Nx compared to WT 5/6 Nx (1.87±0.09 vs. 1.66±0.13 nmol/mL plasma respectively, p=0.0013). KO sham rats exhibited a markedly reduced Cin compared to WT sham (0.465±0.080 vs. 0.574±0.104 mL/min/100g respectively, p=0.085). CONCLUSION: The absence of endogenous carnosine affects redox balance in both skeletal muscle and renal tissue. We identified a crucial role of endogenous carnosine in maintaining renal homeostasis.
Read CV Andressa FormalioniECSS Paris 2023: OP-PN13