bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atorvastatin Reduces Adipose Tissue Browning And Prolong Survival In Cancer Cachexia Mice
Authors: Henriques Felipe Santos , Franco Felipe , Lopes Magno , Santos Kaltinaitis , Guilherme Adilson , Junior Miguel Luiz Batista 
Published: November 2023

Background and aimsCancer cachexia (CC) is a wasting syndrome characterized by systemic inflammation, body weight loss, atrophy of white adipose tissue (WAT) and skeletal muscle. Epidemiological data show that 60–80% of advanced cancer patients are affected by the syndrome, in which 22–40% of deaths are due to CC. During the development of cancer cachexia, a well‐characterized loss of both WAT and skeletal muscle occurs. White‐to‐brown adipose tissue remodeling (browning) in response to CC was demonstrated to take place early during CC stages, before skeletal muscle atrophy. WAT browning is associated with an increased expression of uncoupling protein 1 (UCP1), which leads to increased lipid mobilization and energy expenditure in CC mice. Recently, atorvastatin (ATOR) was proposed to exhibit anti‐cancer properties, including a reduction in adipose tissue loss; nevertheless, few studies have evaluated its effect on survival and WAT browning.MethodsMale C57BL/6 mice (6–8 week‐old) were subcutaneously inoculated with 300μl (3,5×105) of Lewis Lung Carcinoma (TB) and vehicle‐saline (control). Daily oral treatment with Atorvastatin (Citolar®, Pfizer) (100mg/kg per day) or vehicle was started 1 week before tumor cell injection. Samples of different AT depots were collected at day 27 stored at −80° C (5 to 8 animals per each group). Morphological and immunohistochemistry analyses were obtained by light microscopy, while the gene expression analysis was performed by qPCR. For survival studies, rats received daily oral ATOR or vehicle for up to 27 days. Tumor induction was successful in 100% of the animals.ResultsATOR treatment reduced WAT browning cachexia‐induced in TB, showing down‐regulation of both gene and protein expression of UCP1 in SCAT (p< 0,01). Subcutaneous adipose tissue mass loss was attenuated in ATOR when compared with TB (25%, p<0.05). In addition, life span increased (29%, P<0.05) as well as treated animals survived for a significantly longer time than TB group. WAT demonstrated a decrease in TNFa, CD68 and CD3 positive cells in the ATOR when compared to with TB.ConclusionIn the present study we demonstrated that ATOR treatment seems to be efficient in to attenuate classical cachexia marker such as adipose tissue loss followed by an attenuated browning effect induced by cachexia. In addition, ATOR treatment was efficient into increase both life span and survival end point.Support or Funding InformationFinancial Support: 15/19259–0
Examining the Impact of Different Exercise Protocols on PGC‐1α and FNDC5 mRNA Expression in Human Skeletal Muscle
Authors: Bonafiglia Jacob T. , Edgett Brittany A. , Scribbans Trisha D. , Little Jonathan P. , Gurd Brendon J. 
Published: November 2023

A recent overexpression model demonstrated that peroxisome proliferator‐activated receptor coactivator 1‐alpha (PGC‐1α) regulates the expression of fibronectin type III domain containing protein 5 (FNDC5); a novel myokine with a potential role in stimulating brown‐fat‐like development in white adipose tissue. Although FNDC5 mRNA expression remains unaltered following an acute bout of endurance exercise (END) and high intensity interval training (HIIT), it is unclear whether FNDC5 mRNA expression increases following aerobic exercise protocols that demonstrate elevations in PGC‐1α mRNA expression. Therefore, the purpose of the present study was to test the hypothesis that aerobic exercise protocols that increase PGC‐1α mRNA expression will concomitantly increase FNDC5 mRNA expression in human skeletal muscle. Skeletal muscle biopsies were obtained from healthy men at rest (PRE) and three hours after one bout of moderate intensity interval exercise (MIIT; n = 10; 11 one‐minute intervals at 73% WR at VO2peak separated with one‐minute rest periods), HIIT (n = 10; 8 one‐minute intervals at 100% WR at VO2peak separated with one‐minute rest periods), or sprint interval training (SIT; n = 14; 8 20‐second intervals at 170% WR at VO2peak separated with 10 second rest periods). All samples and PGC‐1α mRNA expression data were obtained from previously published studies (1,2). PGC‐1α mRNA expression significantly (p < 0.05) increased following MIIT (+393% ± 345%), HIIT (+720% ± 392%), and SIT (+284% ± 140%). However, FNDC5 mRNA expression did not change following acute MIIT (−8% ± 29%, p = 0.3), HIIT (+16% ± 32%, p = 0.3), or SIT (−5% ± 18%, p = 0.3). Furthermore, changes in PGC‐1α and FNDC5 mRNA expression did not significantly correlate following any exercise protocol. This study demonstrates that although PGC‐1α mRNA expression increased following all exercise protocols, FNDC5 mRNA did not change. Therefore, these results suggest that interval exercise protocols that induce increases in PGC‐1α mRNA expression do not increase FNDC5 mRNA expression.Support or Funding InformationThis study was supported by funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) to J.T.B., J. P. L., and B.J.G. B. A. E. and T. D. S. were supported by Ontario Graduate Scholarships. J. P. L. was also supported by a Canadian Institutes of Health Research (CIHR) New Investigator Award.
Muscle contractile activity regulates SDF‐1α/CXCL12 expression in skeletal muscle
Authors: Yamada Mami , Hokazono Chihiro , Tokizawa Ken , Marui Shuri , Iwata Masahiro , Suzuki Katsuhiko , Miura Shinji , Nagashima Kei , Okutsu Mitsuharu 
Published: November 2023

ObjectiveExercise training induces an increase in capillarity density in skeletal muscle. Chemokines, a family of 8‐ to 10‐kDa chemotactic cytokines, provide signals that regulate cell distribution, differentiation and migration through transmembrane receptors coupled to heterotrimeric GTP‐binding proteins. Among various chemokines, stromal cell‐derived factor‐1 (SDF‐1α/CXCL12) seems to be a key chemokine to control endothelial cell migration. The aim of this study was to examine whether muscle contractile activity regulates CXCL12 expression in skeletal muscle.MethodsMale C57BL/6 mice were individually housed in cages equipped with a running wheel for 4 weeks. Oxidative soleus, plantaris and gastrocnemius with mixed fiber types, and glycolytic white vastus lateralis muscle were harvested at 24 hours after exercise training periods to measure mRNA expression and protein. Gastrocnemius muscle was harvested from muscle‐specific PGC‐1α transgenic mice (PGC‐1αTg) to measure CXCL12 protein. C2C12 myoblasts and myotubes were cultured for 1, 6 and 24 hours with or without mechanical stretch. Total RNA was isolated at 1 and 6 hours after stretch to measure CXCL12 mRNA expression. Protein was isolated at 24 hours after stretch to measure CXCL12 protein. Medium from cultured C2C12 myoblasts and myotubes were also collected at 24 hours after stretch to measure CXCL12 protein.ResultsCXCL12 mRNA and protein in soleus muscle was higher than white vastus lateralis muscle. Voluntary running resulted in increased CXCL12 mRNA and protein in gastrocnemius muscle. PGC‐1αTg mice expressed higher CXCL12 protein compared to wild‐type littermate. Mechanical stretch increased CXCL12 mRNA but not protein in C2C12 myotube. CXCL12 protein in medium from stretched C2C12 myotube increased by mechanical stretch. CXCL12 mRNA expression and protein in C2C12 myoblast has no effect to mechanical stretch.ConclusionsMuscle contractile activity regulates CXCL12 expression in skeletal muscle, which may contribute to exercise‐induced angiogenesis in skeletal muscle.Support or Funding InformationGrant‐in‐Aid for Challenging Exploratory Research (16K13019) and Grant‐in‐Aid for Scientific Research (B) (15H03080) to Okutsu M.
Voluntary Wheel Running in Mice Is Safe During Vaccinia Virus Infection and Does not Impair Vaccine Responses
Authors: Pence Brandt D. , Ryerson Melissa R. , Bravo‐Cruz Ariana G. , Woods Jeffrey A. , Shisler Joanna L. 
Published: November 2023

Vaccinia virus (VACV) is a double‐stranded DNA virus of the poxvirus family. Since the eradication of smallpox, VACV is most commonly used as an experimental infection model, but VACV‐based vaccines (either live or attenuated) have received increased attention in previous years as vehicles for inoculation against other agents. Exercise has previously been shown to impair immune responses to viral infections. Although this has primarily been described in intense exercise, to our knowledge no study has examined voluntary wheel running (VWR) in mice, which impacts immune responses differently compared to forced exercise. Therefore, we examined the impact of VWR on infection and antibody responses to several strains of VACV. Male C57Bl/6J mice ran for 8 weeks on wheels or remained sedentary, then were infected with 10^5 PFU of pathogenic VACV strain Western Reserve (WR) intranasally or inoculated with 10^6 PFU of replication‐deficient VACV strain Modified Vaccinia Ankara (MVA) intraperitoneally. Mice receiving WR were followed for morbidity and mortality for 14 days, while mice receiving MVA had blood collected prior to inoculation and at week 1, 2, and 4 post‐inoculation for examination of antibody responses. VWR in mice did not alter mortality or body weight loss due to WR infection, although food intake was significantly reduced in sedentary mice (p=0.05), indicating a potential protective effect of VWR against morbidity. VWR also did not alter anti‐VACV IgG response, although mice with wheel access had non‐significantly increased IgG (p=0.22). In conclusion, VWR is safe prior to and during VACV infection and does not impair vaccine responses to the attenuated MVA strain. VWR may increase immune responses and reduce morbidity, although the present study was underpowered to determine this.Support or Funding InformationFunded by a grant from the American College of Sports Medicine to BDP.
Regulation of Erythropoietin Expression in Response to Exercise in Mouse and Human Skeletal Muscle
Authors: Edgett Brittany A. , Farquharson Laura , Romanova Nadya , Brunt Keith R. , Gurd Brendon J. , Simpson Jeremy A. 
Published: November 2023

Erythropoietin (EPO) is the master regulator of erythropoiesis and also plays a role in cytoprotection, cell proliferation and heart contractility. In human skeletal muscle, EPO mRNA expression increases in response to acute exercise, however, whether glycolytic or oxidative muscle fibers differentially produce EPO is unknown. Thus, the purpose of this study was to examine EPO mRNA expression in oxidative and glycolytic muscles following acute exercise in mice. Further, we also examined whether training status had an effect on EPO expression. Experiment 1 involved young healthy men (age, 21.4 ± 2.8 years; VO2peak, 47.1 ± 11.8 mL min−1 kg−1) from a previously published study (Edgett et al. 2016) who performed a single bout of exercise at ~55% of peak aerobic work rate for 1 hour. Muscle biopsies were obtained from the vastus lateralis at rest and 3 hours post‐exercise. Experiment 2 involved 8 week‐old male C57/B6 mice that were either exercise‐trained by treadmill running (1 hour/day, 4 days/week) or remained sedentary (untrained) for 5 weeks. Following the intervention, all mice performed an exhaustive exercise bout that began at a speed of 12 m/min with a 20‐degree grade; speed was subsequently increased by 1 m/min at 2, 5, 10, 20, 30 and 40 min, or until mice reached exhaustion. Soleus (oxidative muscle) and extensor digitorum longus (EDL, glycolytic muscle) were harvested at 1, 2 and 4 hours post‐exercise. All samples were analyzed by real‐time qPCR for changes in EPO mRNA expression. In agreement with a previous report, EPO mRNA expression increased 14 ± 5% in human skeletal muscle 3 hours post‐exercise. In experiment 2, EPO expression increased 4.1 ± 2.8 and 7.4 ± 1.7 fold at 1 hour post‐exercise in the soleus muscle of untrained and trained mice, respectively, before returning towards baseline. In EDL, post‐exercise EPO expression increased 4.1 ± 1.0 fold by 2 hours and plateaued thereafter in only untrained mice; this response was blunted in trained mice. Here we show that EPO expression increased post‐exercise in both glycolytic and oxidative murine skeletal muscles; training had a fiber‐type‐specific differential effect in these muscles. Future studies should determine the physiological significance of skeletal muscle‐derived EPO.Support or Funding InformationThis study was supported by funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) to B.A.E., K.R.B., B.J.G. and J.A.S.
A role for focal adhesion kinase in the contraction of murine gastric fundus smooth muscle evoked by cholinergic neurotransmission
Authors: Xie Yeming , Perrino Brian 
Published: November 2023

Cholinergic neurotransmission‐induced smooth muscle contraction involves the regulation of myosin light chain (LC20) phosphorylation and dephosphorylation by myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP). C‐kinase potentiated protein phosphatase‐1 inhibitor protein of 17 kDa (CPI‐17), and myosin phosphatase target subunit 1 (MYPT1) are crucial for gastrointestinal smooth muscle contractile regulation via their inhibition of MLCP activity. Besides these mechanisms, integrin‐mediated cell‐matrix adhesions connect the cytoskeleton with the extracellular matrix to facilitate cohesion and to generate tension throughout the whole muscle in response cholinergic neurotransmission. Cell‐matrix adhesions and integrin signaling involve the dynamic recruitment and assembly of several proteins, primarily focal adhesion kinase (FAK), at the adhesive site. FAK is a tyrosine kinase whose phosphorylation state and activity is tightly linked with cell adhesion to the extracellular matrix through integrin receptors. FAK participates in transmitting the force generated by the activation of contractile proteins in smooth muscle cells (SMC), to the extracellular matrix filaments and throughout the smooth muscle tissue.Here, we address the hypothesis that FAK activation is involved in the contraction of gastric fundus smooth muscle in response to cholinergic stimulation. FAK (not Pyk2) was identified as a major tyrosine‐phosphorylated protein in response to electric field stimulation (EFS). EFS in the presence of L‐NNA and MRS2500 contracted gastric fundus smooth muscle strips and significantly increased FAK phosphorylation at Tyr397. In addition, EFS increased the association of FAK with Beta‐1 integrin. The FAK inhibitor PF‐431396 inhibited the EFS‐stimulated contractions, the increase in FAK Tyr397 phosphorylation, and the association of FAK with Beta‐1 integrin. PF‐431396 also blocked the EFS‐induced increase in MYPT1 Thr853, CPI‐17 Thr38, and LC20 Ser19 phosphorylation. The muscarinic acetylcholine receptor antagonist atropine, but not the L‐type Ca2+ channel blocker nicardipine, prevented the EFS‐induced increase in FAK Tyr397 phosphorylation. However, FAK Tyr397 phosphorylation was increased during high K+‐induced contraction, and both were inhibited by PF‐431396. Our findings demonstrate that FAK Tyr397 phosphorylation and association with integrin receptors in SMC plays a role in the contractile response of gastric fundus smooth muscles to cholinergic transmission.Support or Funding InformationThis project was supported by a Takeda Innovation Center Grant, Takeda Pharmaceuticals, Takeda California, San Diego, CA 92121
S. aureus induction of Hif1α drives airway epithelial inflammatory signaling
Authors: Jurado Andrea , Wickersham Matthew , Lung Tania Wong Fok , Miller Alex , Parker Dane , Prince Alice 
Published: November 2023

RATIONALEStaphylococcus aureus is a major cause of healthcare associated pneumonia and leads to high morbidity and mortality rates. Immune cells depend on glycolysis, particularly through Hif1α signaling, to drive pro‐inflammatory defenses to clear bacterial infections. We postulated that airway epithelial cells similarly use Hif1α stabilization and glycolysis to defend against S. aureus infection.METHODSA proteomic analysis of bronchoalveolar lavage fluid (BALF) from S. aureus USA300 infected C57BL/6 mice was performed comparing infected and uninfected mice. The metabolic and immunological consequences of Hif1a signaling were demonstrated in vitro. Human bronchial epithelial (16HBE) cells were studied through qRT arrays, western blots and ELISAs.RESULTSS. aureus wild type USA300 (WT) were found to activate the canonical Hif1a and metabolic pathways that support glycolysis, as defined by the Ingenuity Pathway Analysis (IPA) of the secreted proteins in the BALF of infected mice. These results were verified in immunoblots demonstrating that S. aureus WT and toxin‐deficient agr mutants both stabilize Hif1α in 16HBE cells, despite significantly increased intracellular accumulation of the agr strain. Increased Hif1α corresponded with increased IL‐1b, IL‐8 and phosphofructokinase 1 (PFK1) transcript levels under infected conditions. The induction of HIF1a signaling, as a consequence of the metabolic stress caused by infection, was dependent on the glycolytic capacities of the bacteria, as a glycolytic mutant of S. aureus lacking pyruvate kinase (pyk) failed to induce Hif1α or secrete pro‐inflammatory cytokines IL‐1β and IL‐18. This was in contrast to WT and phosphoenolpyruvate kinase (pckA) deficient strains, with impaired gluconeogenesis.CONCLUSIONSThe induction of epithelial glycolysis contributes to the metabolic and inflammatory response to S. aureus pulmonary infection. Both the organisms and the host use glycolysis to meet their increased metabolic requirements, promoting competition for glucose and stimulating Hif1a signaling. Our data highlights that metabolic stress is a driving factor in the host response to S. aureus in the lung, suggesting that manipulating metabolism might be a novel approach in the prevention and treatment of bacterial pneumonia.Support or Funding InformationFUNDING: NIH R35 HL135300
Rupture of Cancer Cells Under Microcirculatory Conditions
Authors: Kamyabi Nabiollah , Vanapalli Siva 
Published: November 2023

Survival of circulating tumor cells (CTCs) in blood circulation is essential for cancer metastasis. However, fluid forces in microcirculation have been shown to cause cell rupture, lending to the notion that such mechanical trauma of CTCs is responsible for metastatic inefficiency. Literature evidence for tumor cell death due to mechanical damage remains ambiguous and moreover the physical mechanisms of cell rupture are poorly understood. Here, we develop a microfluidic capillary model of microcirculation that contains an array of flow bifurcations and investigate rupture of tumor cells. We find that when a cancer cell arrives at a narrow bifurcation, it is temporarily arrested, followed by strong cellular deformation causing a cytosol‐filled membrane‐bound vesicle to be pinched‐off. The vesicle size was found to increase with the size of tumor cell suggesting that the cytosol content is larger for bigger cells. To identify the essential features of the mechanism underlying the rupture process, we used a library of drugs that (i) either enhance or inhibit the polymerization of actin and microtubules (ii) inhibit myosin II and decrease cortical tension, and (iii) condense and decondense nuclear chromatin. Results from these studies show that the cytoskeletal elements and membrane play an important role in regulating the time‐scale for rupture of tumor cells, but not the nucleus. The vesicle size was not sensitive to any of the drug treatments indicating again that the cytosol content determines the vesicle volume. Collectively, the drug studies support the poroelastic model of a cell, where under mechanical stress, the cytosol flows through the elastic cytoskeleton and fills the membrane that is detached from the cortex. Experiments with different cancer cell lines showed that highly metastatic cells take longer to rupture suggesting that their cytoskeleton and membrane properties are different than weakly metastatic cell lines. Finally, we find that less than 5% of the fragmented tumor cells undergo apoptosis, suggesting that CTCs can survive the impact of fluid forces in microcirculation and that mechanical trauma is not a significant cause for metastatic inefficiency.Support or Funding InformationCancer Prevention and Research Institute of Texas (Grant No. RP 140298)
KLF15 is modulated by leucine in skeletal muscle submitted to immobilization in rats
Authors: Zuanazzi Flávia Aparecida Graça , Bento Mirella , Silvestre João Guilherme , Moriscot Anselmo Sigari 
Published: November 2023

Leucine is a branched chain amino acid known not only as a component of proteins, but also as a pharmacological agent, which promotes important anti‐catabolic effects, mitigating muscle atrophy. Previous studies from our laboratory demonstrated that daily administration of leucine was able to attenuate the weight loss in soleus muscle and cross‐sectional area after 7 days unilateral immobilization of the left hind limb. This protective effect of leucine was correlated with reduced gene expression of key components of the Ub‐proteasome proteolytic system atrogin‐1 and MuRF1. The understanding of regulatory factors involved in the anticatabolic effects of leucine is of great interest. Accordingly, the Krüppel like factor 15 (KLF15) is a recently discovered transcriptional factor that is involved in skeletal muscle atrophy at least in part by upregulating atrogin‐1 and MuRF1 gene expression. In this study, our hypothesis contemplates that KLF15 is involved in the anti‐catabolic effects of leucine.The protocols used in this study submitted and approved by Institute of Biomedical Sciences/University of São Paulo – Ethical Committee for Animal Research (#99/2015). Male Wistar rats (n=6 per group), 2 months old, weighing 260g, were divided into four groups: control (untreated animal), leucine supplemented only, immobilized (left hind limb immobilization), immobilized and leucine supplemented. Leucine was orally administered (via gavage) once a day in a dose of 2.7 g/kg body mass per days for 7 days. Monolateral hind limb immobilization was performed in the left hind limb by applying a cast with total plantar flexion and knee extension. Rats were killed after 7 days and soleus muscle removed. Protein and mRNA expression were analyzed by Western Blotting and RT‐PCR, respectively. Intracellular localization of KLF15 was determined by immunofluorescent analysis.Immobilization for 7 days resulted in an increased in protein (50%) and mRNA (100%) levels of KLF15 in soleus muscle from rats, nonetheless not altered by leucine supplementation. Interestingly, immobilization for 7 days enhanced nuclear localization of KLF15, which was reduced by leucine supplementation in soleus muscle from immobilized group.These results suggest that the anti‐catabolic effects of leucine involve blocking KLF15 action.Support or Funding InformationSupported by Postdoctoral fellowship PNPD‐CAPES e FAPESP 2015/04090‐0.