Cristina Bárcena

Objetivo: El objetivo de este estudio fue analizar si la potencia es un buen indicador del rendimiento en competiciones de bicicleta todo terreno (BTT), específicamente en la SuperCup cross country olímpico (XCO) BTT de Banyoles-España. Metodología: Se monitorizó la potencia de 10 ciclistas hombres profesionales de XCO-BTT durante la carrera y se analizó su relación con el rendimiento durante las subidas, las bajadas y los tramos llanos de la vuelta más rápida. Resultados: Se encontró una correlación fuerte entre el rendimiento y la potencia media (Potmed) (R² = -.652, p = .041), y muy fuerte entre el rendimiento y la potencia relativa (Potrel) (R² = -.887, p = .001); durante las subidas, la correlación fue fuerte entre el rendimiento y la Potmed (R² = -.719, p = .019), y muy fuerte entre el rendimiento y la Potrel (R² = -.888, p = .001). La relación entre el rendimiento y la Potmed durante los tramos llanos fue fuerte (R² = -.780, p = .008), y muy fuerte entre el rendimiento y la Potrel (R² = -.821, p = .004). Durante las bajadas no se encontró correlación entre el rendimiento y la Potmed y se encontró una correlación moderada entre el rendimiento y la Potrel (R² = -.530, p = .115). Discusión: Este estudio destaca la importancia de la Potrel como indicador del rendimiento en las competiciones de XCO-BTT. Conclusiones: El gran hallazgo de este estudio ha sido que la potencia no es un buen indicador del rendimiento durante las bajadas, donde este parece determinado por aspectos técnicos de conducción.

Consequences of running mountain races on muscle damage were investigated by analysing serum muscle enzymes and fibre-type-specific sarcomere proteins. We studied 10 trained amateur and 6 highly trained runners who ran a 35 km and 55 km mountain trail race (MTR), respectively. Levels of creatine kinase (CK), CK-MB isoform (CK-MB), sarcomeric mitochondrial CK (sMtCK), transaminases (AST and ALT), cardiac troponin I (cTnI) and fast (FM) and slow myosin (SM) isoforms, were assessed before, 1 h, 24 h and 48 h after the beginning of MTR. Significant SM increases were found at 24 h in the 55 km group. Levels of CK, CK-MB, AST and cTnI were significantly elevated in both groups following MTR, but in the 55 km group they tended to stabilize in at 48 h. Using pooled data, time-independent serum peaks of SM and CK-MB were significantly correlated. Moreover, concentration of sMtCK was significantly elevated at 1 and 24 h after the race in the 35 km group. Although training volume could confer protection on the mitochondria, the increase in serum CK-MB and SM in the 55 km group might be related to damage to the contractile apparatus type I fibres. Competing in long-distance MTRs might be related to deeper type I muscle fibre damage, even in highly trained individuals

CD5‐like (CD5L) is a soluble scavenger cysteine‐rich protein that modulates inflammatory responses. We studied the involvement of CD5L in liver cancer. Immunohistochemistry (IHC) of CD5L in 60 hepatocellular carcinomas and 34 adjacent nontumor livers, showed that CD5L staining was higher in tumor than in nontumor tissue (Mann‐Whitney test; P = 0.0039). High CD5L correlated with elevated proliferation (Ki67, linear regression; P < 0.0001) and lower patient event‐free survival (log‐rank; P = 0.0185). Accordingly, CD5L expression was detected in the liver cancer cell lines Huh7, HepG2, and SNU‐398. In vitro technologies using these cell lines, including small interfering RNA (siRN A ) and cDNA transfection, showed that CD5L promoted colony formation and cell proliferation and protected against cisplatin‐induced apoptosis. To find a molecular explanation for these roles, novel CD5L‐interacting protein ligands in liver cancer cells were identified by immunoprecipitation followed by mass spectrometry. Among these, the molecular chaperone of the unfolded protein response (UPR), heat shock protein (HSP)‐A5, was selected for validation. The interaction was confirmed by confocal microscopy in the Huh7 and HepG2 cell lines. Furthermore, functional experiments revealed that CD5L activates the UPR and autophagy mechanisms in Huh7 cells, thereby providing a novel molecular link between the UPR and autophagy in liver cancer.—Aran, G., Sanjurjo, L., Barcena, C., Simon‐Coma, M., Tellez, E., Vazquez‐Vitali, M., Garrido, M., Guerra, L., Díaz, E., Ojanguren, I., Elortza, F., Planas, R., Sala, M., Armengol, C., Sarrias, M.‐R. CD5L is upregulated in hepatocellular carcinoma and promotes liver cancer cell proliferation and antiapoptotic responses by binding to HSPA5 (GRP78). FASEB J. 32, 3878–3891 (2018). www.fasebj.org

Targeting glucosylceramide synthase upregulation reverts sorafenib resistance in experimental hepatocellular carcinoma

Hepatocellular carcinoma (HCC) frequently develops in a pro-inflammatory and pro-fibrogenic environment with hepatic stellate cells (HSCs) remodeling the extracellular matrix composition. Molecules secreted by liver tumors contributing to HSC activation and peritumoral stromal transformation remain to be fully identified. Here we show that conditioned medium from HCC cell lines, Hep3B and HepG2, induced primary mouse HSCs transdifferentiation, characterized by profibrotic properties and collagen modification, with similar results seen in the human HSC cell line LX2. Moreover, tumor growth was enhanced by coinjection of HepG2/LX2 cells in a xenograft murine model, supporting a HCC-HSC crosstalk in liver tumor progression. Protein microarray secretome analyses revealed angiogenin as the most robust and selective protein released by HCC compared to LX2 secreted molecules. In fact, recombinant angiogenin induced in vitro HSC activation requiring its nuclear translocation and rRNA transcriptional stimulation. Moreover, angiogenin antagonism by blocking antibodies or angiogenin inhibitor neomycin decreased in vitro HSC activation by conditioned media or recombinant angiogenin. Finally, neomycin administration reduced tumor growth of HepG2-LX2 cells coinjected in mice. In conclusion, angiogenin secretion by HCCs favors tumor development by inducing HSC activation and ECM remodeling. These findings indicate that targeting angiogenin signaling may be of potential relevance in HCC management.

Growth arrest–specific gene 6 (GAS6) promotes growth and cell survival during tissue repair and development in different organs, including the liver. However, the specific role of GAS6 in liver ischemia/reperfusion (I/R) injury has not been previously addressed. Here we report an early increase in serum GAS6 levels after I/R exposure. Moreover, unlike wild-type (WT) mice, Gas6 −/− mice were highly sensitive to partial hepatic I/R, with 90% of the mice dying within 12 hours of reperfusion because of massive hepatocellular injury. I/R induced early hepatic protein kinase B (AKT) phosphorylation in WT mice but not in Gas6 −/− mice without significant changes in c-Jun N-terminal kinase phosphorylation or nuclear factor kappa B translocation, whereas hepatic interleukin-1β (IL-1β) and tumor necrosis factor (TNF) messenger RNA levels were higher in Gas6 −/− mice versus WT mice. In line with the in vivo data, in vitro studies indicated that GAS6 induced AKT phosphorylation in primary mouse hepatocytes and thus protected them from hypoxia-induced cell death, whereas GAS6 diminished lipopolysaccharide-induced cytokine expression (IL-1β and TNF) in murine macrophages. Finally, recombinant GAS6 treatment in vivo not only rescued GAS6 knockout mice from severe I/R-induced liver damage but also attenuated hepatic damage in WT mice after I/R. Conclusion: Our data have revealed GAS6 to be a new player in liver I/R injury that is emerging as a potential therapeutic target for reducing postischemic hepatic damage. (Hepatology 2010;)

Hypoxia-mediated HIF-1α stabilization and NF-κB activation play a key role in carcinogenesis by fostering cancer cell survival, angiogenesis and tumor invasion. Gangliosides are integral components of biological membranes with an increasingly recognized role as signaling intermediates. In particular, ganglioside GD3 has been characterized as a proapoptotic lipid effector by promoting cell death signaling and suppression of survival pathways. Thus, our aim was to analyze the role of GD3 in hypoxia susceptibility of hepatocarcinoma cells and in vivo tumor growth. We generated and characterized a human hepatocarcinoma cell line stably expressing GD3 synthase (Hep3B-GD3), which catalyzes the synthesis of GD3 from GM3. Despite increased GD3 levels (2–3 fold), no significant changes in cell morphology or growth were observed in Hep3B-GD3 cells compared to wild type Hep3B cells under normoxia. However, exposure of Hep3B-GD3 cells to hypoxia (2% O₂) enhanced reactive oxygen species (ROS) generation, resulting in decreased cell survival, with similar findings observed in Hep3B cells exposed to increasing doses of exogenous GD3. In addition, hypoxia-induced c-Src phosphorylation at tyrosine residues, NF-κB activation and subsequent expression of Mn-SOD were observed in Hep3B cells but not in Hep3B-GD3 cells. Moreover, MnTBAP, an antioxidant with predominant SOD mimetic activity, reduced ROS generation, protecting Hep3B-GD3 cells from hypoxia-induced death. Finally, lower tumor growth, higher cell death and reduced Mn-SOD expression were observed in Hep3B-GD3 compared to Hep3B tumor xenografts. These findings underscore a role for GD3 in hypoxia susceptibility by disabling the c-Src/NF-κB survival pathway resulting in lower Mn-SOD expression, which may be of relevance in hepatocellular carcinoma therapy.