Rats prefer condensed milk to strawberry jam - a new possibility for voluntary oral drug administration.

Voluntary oral drug administration using sweet substances promotes rodents' therapeutic compliance while reducing stress induced by forced drug administration. We aimed to test whether rats would willingly eat strawberry jam or condensed milk from a syringe, and which one they would prefer. Our results show that rats prefer condensed milk, demonstrating its potential as a vehicle for the voluntary oral administration of drugs in experimental protocols.

Heterogeneity in protocols and outcomes to study the effect of renin-angiotensin system blockers in inflammatory bowel disease: A systematic review.

BACKGROUND: The renin-angiotensin system (RAS) has been associated with inflammatory bowel disease (IBD), supporting translational relevance of RAS blockers. Comparability of study design/outcomes is fundamental for data analysis/discussion. OBJECTIVES: We aimed at evaluating the heterogeneity among protocols and outcomes to study the effect of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in IBD. METHODS: This study was performed and reported in accordance with the Cochrane recommendations and PRISMA (PROSPERO-CRD42022323853). Systematic searches were performed in PubMed, Scopus and Web of Science. Studies that met the inclusion criteria were selected. Quality assessment of the studies was done with the SYRCLES's risk of bias tools for animal studies. RESULTS: Thirty-five pre-clinical studies and six clinical studies were included. Chemical induction of colitis was the most used model, but variable doses of the induction agent were reported. All studies reported at least a disease activity index, a macroscopic score, or a histologic assessment, but these scores were methodologically heterogeneous and reported for different characteristics. Great heterogeneity was also found in drug interventions. Inflammatory markers assessed as outcomes were different across studies. CONCLUSION: Lack of standardization of protocols and outcomes among studies threatens the evidence on how RAS blockers influence IBD outcomes.

A cytokine-induced spheroid-based in vitro model for studying osteoarthritis pathogenesis.

Given the lack of in vitro models faithfully reproducing the osteoarthritis (OA) disease on-set, this work aimed at manufacturing a reliable and predictive in vitro cytokine-based Articular Cartilage (AC) model to study OA progression. Cell spheroids of primary human fetal chondrocytes (FCs) and h-TERT mesenchymal stem cells differentiated chondrocytes (Y201-C) were analysed in terms of growth kinetics, cells proliferation and apoptosis over 10 days of culture, in healthy condition or in presence of cytokines (interleukin-1ß, -6 and TNF-α). Then, the spheroids were assembled into chondrospheres using a bottom-up strategy, to obtain an in vitro cytokines-induced OA model. The resulting chondrospheres were evaluated for gene expression and anabolic ECM proteins. Compared to the healthy environment, the simulated OA environment induced chondrocyte hyperproliferation and apoptotic pathway, decreased expression of anabolic ECM proteins, and diminished biosynthetic activity, resembling features of early-stage OA. These characteristics were observed for both Y201-C and HC at high and low concentrations of cytokines. Both HC and Y201-C demonstrated the suitability for the manufacturing of a scaffold-free in vitro OA model to facilitate studies into OA pathogenesis and therapeutic strategies. Our approach provides a faithful reproduction of early-stage osteoarthritis, demonstrating the ability of obtaining different disease severity by tuning the concentration of OA-related cytokines. Given the advantages in easy access and more reproducible performance, Y201-C may represent a more favourable source of chondrocytes for establishing more standardized protocols to obtain OA models.

ACE and ACE2 catalytic activity in the fecal content along the gut.

BACKGROUND: Angiotensin-converting enzyme (ACE) and ACE2 are two major enzymes of the renin-angiotensin-aldosterone system (RAAS), which control the formation/degradation of angiotensin (Ang) II and Ang1-7, regulating their opposite effects. We aimed at evaluating the catalytic activity of ACE and ACE2 in the intestinal content and corresponding intestinal tissue along the gut of Wistar Han rats. METHODS: Portions of the ileum, cecum, proximal colon, and distal colon, and the corresponding intestinal content were collected from Wistar Han rats. Enzyme activity was evaluated by fluorometric assays using different substrates: Hippuryl-His-Leu for ACE-C-domain, Z-Phe-His-Leu for ACE-N-domain, and Mca-APK(Dnp) for ACE2. ACE and ACE2 concentration was assessed by ELISA. Ratios concerning concentrations and activities were calculated to evaluate the balance of the RAAS. Statistical analysis was performed using Friedman test followed by Dunn's multiple comparisons test or Wilcoxon matched-pairs test whenever needed. KEY RESULTS: ACE and ACE2 are catalytically active in the intestinal content along the rat gut. The ACE N-domain shows higher activity than the C-domain both in the intestinal content and in the intestinal tissue. ACE and ACE2 are globally more active in the intestinal content than in the corresponding intestinal tissue. There was a distal-to-proximal prevalence of ACE2 over ACE in the intestinal tissue. CONCLUSIONS & INFERENCES: This work is the first to report the presence of catalytically active ACE and ACE2 in the rat intestinal content, supporting future research on the regulatory role of the intestinal RAAS on gut function and a putative link to the microbiome.

Effect of Protective Measures Adopted in the COVID-19 Pandemic on Hemodialysis Patients.

Introduction The use of masks and other preventive measures is nowadays an essential measure to prevent COVID-19 infections, particularly in hemodialysis patients. The aim of this study was to understand whether these protective measures adopted during the COVID-19 pandemic reduced or somehow contained the number of respiratory infections in a population of hemodialysis patients. Methods This was a longitudinal retrospective single-center study of hemodialysis patients with at least six months of follow-up in a central hospital. A total of 103 patients were evaluated for the study. Two groups were defined: a control group that was followed in the year before the beginning of the pandemic and a group that followed in the year after its beginning. Results Patients in the pandemic group had a higher prevalence of previous major cardiovascular events (48.9% vs 8.6%) and heart failure (31.3% vs 12.1%) than those in the control group. Vaccination rates for influenza and pneumococcus as well as the monthly analytical results were similar in both groups. There were no significant differences in lower respiratory infections, hospitalizations caused by lower respiratory infections, and mortality between both groups. However, not accounting for aspiration pneumonias, the pandemic group had half the mortality due to respiratory infections (2.2% vs 5.2%). Conclusion Despite patients in the pandemic group having a similar prevalence of respiratory infections and hospitalizations motivated by lower respiratory infections, they presented about half the mortality of the control group. This suggests that although there was no decrease in the number of infections, protective measures may have contributed to a decreased mortality.

Association between blood pressure and angiotensin-converting enzymes activity in prepubertal children ∗.

OBJECTIVES: Angiotensin-converting enzymes' (ACEs) relationship with blood pressure (BP) during childhood has not been clearly established. We aimed to compare ACE and ACE2 activities between BMI groups in a sample of prepubertal children, and to characterize the association between these enzymes' activities and BP. METHODS: Cross-sectional study of 313 children aged 8-9 years old, included in the birth cohort Generation XXI (Portugal). Anthropometric measurements and 24-h ambulatory BP monitoring were performed. ACE and ACE2 activities were quantified by fluorometric methods. RESULTS: Overweight/obese children demonstrated significantly higher ACE and ACE2 activities, when compared to their normal weight counterparts [median (P25-P75), ACE: 39.48 (30.52-48.97) vs. 42.90 (35.62-47.18) vs. 43.38 (33.49-49.89) mU/ml, P for trend = 0.009; ACE2: 10.41 (7.58-15.47) vs. 21.56 (13.34-29.09) vs. 29.00 (22.91-34.32) pM/min per ml, P for trend < 0.001, in normal weight, overweight and obese children, respectively]. In girls, night-time systolic BP (SBP) and diastolic BP (DBP) increased across tertiles of ACE activity ( P < 0.001 and P  = 0.002, respectively). ACE2 activity was associated with higher night-time SBP and DBP in overweight/obese girls ( P  = 0.037 and P  = 0.048, respectively) and night-time DBP in the BMI z-score girl adjusted model ( P  = 0.018). Median ACE2 levels were significantly higher among nondipper girls (16.7 vs. 11.6 pM/min per ml, P  = 0.009). CONCLUSIONS: Our work shows that obesity is associated with activation of the renin-angiotensin-aldosterone system, with significant increase of ACE and ACE2 activities already in childhood. Also, we report sex differences in the association of ACE and ACE2 activities with BP.

Not so Mutually Exclusive Diseases: A Case of Co-occurrence of Inflammatory Spondyloarthritis and Diffuse Skeletal Hyperostosis in a Young Patient.

Diffuse idiopathic skeletal hyperostosis (DISH) and axial spondyloarthritis (axial SpA) are differential diagnoses of lower back pain. While the latter is considered to be an inflammatory disease, DISH is thought to be a metabolic condition. The authors report a case of a 34-year-old man who presented with a one-year history of axial lower back pain associated to migratory polyarthritis, buttock and heel pain. Imaging revealed contiguous calcification of the anterior longitudinal ligament of the cervical segment, meeting major criteria for DISH. However, he also exhibited signs of bilateral sacroiliitis highly suggestive of axial SpA for which he initiated biological therapy. LEARNING POINTS: Although the most used criteria for diffuse idiopathic skeletal hyperostosis (DISH) were designed to exclude radiographic signs of spondyloarthritis (SpA), both conditions can be present simultaneously.There are only few case reports in the literature that demonstrate the association of the two diseases.Overlap and misperception of SpA and DISH could result in undertreatment of individual patients and have a negative impact on prognosis.

An In Vitro Engineered Osteochondral Model as Tool to Study Osteoarthritis Environment.

Osteoarthritis (OA) is a joint degenerative pathology characterized by mechanical and inflammatory damages affecting synovium, articular cartilage (AC), and subchondral bone (SB). Several in vitro, in vivo, and ex vivo models are developed to study OA, but to date the identification of specific pharmacological targets seems to be hindered by the lack of models with predictive capabilities. This study reports the development of a biomimetic in vitro model of AC and SB interface. Gellan gum methacrylated and chondroitin sulfate/dopamine hydrogels are used for the AC portion, whereas polylactic acid functionalized with gelatin and nanohydroxyapatite for the SB. The physiological behavior of immortalized stem cells (Y201s) and Y201s differentiated in chondrocytes (Y201-Cs), respectively, for the SB and AC, is demonstrated over 21 days of culture in vitro in healthy and pathological conditions, whilst modeling the onset of cytokines-induced OA. The key metrics are: lower glycosaminoglycans production and increased calcification given by a higher Collagen X content, in the AC deep layer; higher expression of pro-angiogenic factor (vegf) and decreased expression of osteogenic markers (coll1, spp1, runx2) in the SB. This novel approach provides a new tool for studying the development and progression of OA.

Biological potentialities and chemical composition of Tarenaya aculeata roots and stems

Plant extracts are rich in secondary metabolites responsible for numerous biological activities. This study aimed to evaluate the antioxidant, antibacterial and photoprotective potentials, toxicity and chemical composition of extracts and fractions of stems and roots of Tarenaya aculeata. Phytochemical analyses were performed at qualitative and quantitative levels to evaluate the classes of secondary metabolites. The sun protection factor (SPF) and antioxidant potentials were determined spectrophotometrically, the antibacterial activity was tested against seven bacteria and the toxicity was evaluated using Artemia salina assay. Phytochemical screening revealed the presence of alkaloids, phenolic compounds, flavonoids, glycosides, tannins and saponins. The levels of phenolic compounds, tannins and alkaloids, SPF and antioxidant potentials showed greater results in the stem (SF) and root (RF) fractions in relation to the stem (SE) and root (RE) extracts. All samples exhibited a broad spectrum of antibacterial activity, with MIC values ranging from 31.25 to 250 Hg mL-1. SE, SF and RF caused mortality in A. salina larvae, with LC50 of 347.06, 34.71 and 85.39 ng mL-1, respectively, whereas RE was non-toxic. Thus, T. aculeata is rich in bioactive secondary metabolites, although further studies will be needed to characterize its chemical constituents and investigate their adverse effects.

Los extractos de plantas son ricos en metabolitos secundarios responsables de numerosas actividades biológicas. Este estudio tuvo como objetivo evaluar el potencial antioxidante, antibacteriano y fotoprotector, ademas de la toxicidad y la composición química de extractos y fracciones de tallos y raíces de Tarenaya aculeata. Se realizaron análisis fitoquímicos a nivel cualitativo y cuantitativo para evaluar las clases de metabolitos secundarios. El factor de protección solar (SPF) y los potenciales antioxidantes se determinaron espectrofotométricamente, la actividad antibacteriana se probó contra siete bacterias y la toxicidad se evaluó mediante el ensayo con Artemia salina. El tamizaje fitoquímico reveló la presencia de alcaloides, compuestos fenólicos, flavonoides, glucósidos, taninos y saponinas. Los niveles de compuestos fenólicos, taninos y alcaloides, SPF y potencial antioxidante mostraron mayores resultados en las fracciones de tallo (SF) y raíz (RF) en relación a los extractos de tallo (SE) y raíz (RE). Todas las muestras exhibieron actividad antibacteriana de amplio espectro, con valores de MIC que oscilaron entre 31,25 y 250 Hg mL-1. SE, SF y RF causaron mortalidad en larvas de A. salina, con CL50 de 347,06; 34,71 y 85,39 µg mL-1, respectivamente, mientras que RE no fue tóxico. Por tanto, T. aculeata es rica en metabolitos secundarios bioactivos, aunque se necesitarán más estudios para caracterizar sus componentes químicos e investigar sus efectos adversos.

Extratos vegetais são ricos em metabólitos secundários responsáveis por inúmeras atividades biológicas. Este estudo teve como objetivo avaliar os potenciais antioxidante, antibacteriano e fotoprotetor, toxicidade e composição química de extratos e frações de caules e raízes de Tarenaya aculeata. Análises fitoquímicas foram realizadas em níveis qualitativo e quantitativo para avaliar as classes de metabólitos secundários. Fator de proteção solar (FPS) e potenciais antioxidantes foram determinados espectrofotometricamente, a atividade antibacteriana testada contra sete bactérias e a toxicidade avaliada pelo ensaio com Artemia salina. A triagem fitoquímica revelou a presença de alcaloides, compostos fenólicos, flavonoides, glicosídeos, taninos e saponinas. Os teores de compostos fenólicos, taninos e alcaloides, FPS e potencial antioxidante apresentaram maiores resultados nas frações caule (SF) e raiz (RF) em relação aos extratos de caule (SE) e raiz (RE). Todas as amostras exibiram atividade antibacteriana de amplo espectro, com valores de MIC variando de 31,25 a 250 µg mL-1. SE, SF e RF causaram mortalidade em larvas de A. salina, com LC50 de 347,06, 34,71 e 85,39 Hg mL-1, respectivamente, enquanto RE não foi tóxico. Portanto, T. aculeata é rico em metabólitos secundários bioativos, embora mais estudos sejam necessários para caracterizar seus constituintes químicos e investigar seus efeitos adversos.

Histomorphometry Changes and Decreased Reactivity to Angiotensin II in the Ileum and Colon of Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus (DM) is a chronic progressive metabolic disorder associated with several gastrointestinal complications, affecting up to 75% of patients. Knowing that Angiotensin II (AngII) also regulates intestinal contraction, we decided to evaluate changes in ileum and colon histomorphometry and AngII reactivity in a rat model of DM. Streptozotocin (STZ, 55 mg/kg) was administered to induce DM to 24 adult male Wistar rats. Diabetic rats displayed all the characteristic signs of type 1 DM (T1DM) and fecal excretion increased about 4-fold over 14 days, while the excretion of controls remained unaltered. Compared to controls, diabetic ileum and colon presented an increase in both macroscopic (length, perimeter and weight) and microscopic (muscular wall thickness) parameters. Functionally, AngII-induced smooth muscle contraction was lower in diabetic rats, except in the distal colon. These differences in the contractile response to AngII may result from an imbalance between AngII type 1 (antagonized by candesartan, 10 nM) and type 2 receptors activation (antagonized by PD123319, 100 nM). Taken together, these results indicate that an early and refined STZ-induced T1DM rat model already shows structural remodelling of the gut wall and decreased contractile response to AngII, findings that may help to explain diabetic dysmotility.

Pregnancy and lactation-associated osteoporosis in a Systemic Lupus Erythematosus patient.

Pregnancy and lactation-associated osteoporosis (PLO) is a rare disease that occurs in late pregnancy or early postpartum and is associated with multiple vertebral fractures. We present a case of a 34-year-old woman with a history of Systemic Lupus Erythematosus and Antiphospholipid Syndrome, who started postpartum back pain. After an ineffective response to analgesic escalation, she performed imaging exams with evidence of multiple dorsal and lumbar vertebral fractures. After an exhaustive etiological study, PLO represented the most likely diagnosis. Early diagnosis, interruption of breastfeeding, and initiation of targeted anti-osteoporotic therapy are essential for symptomatic control, increase the quality of life of these patients, and prevent new fractures in the future.

Exploiting Meltable Protein Hydrogels to Encapsulate and Culture Cells in 3D.

There is a growing realization that 3D cell culture better mimics complex in vivo environments than 2D, lessening aberrant cellular behaviors and ultimately improving the outcomes of experiments. Chemically crosslinked hydrogels which imitate natural extracellular matrix (ECM) are proven cell culture platforms, but the encapsulation of cells within these hydrogel networks requires bioorthogonal crosslinking chemistries which can be cytotoxic, synthetically demanding, and costly. Capsular antigen fragment 1 (Caf1) is a bacterial, polymeric, fimbrial protein which can be genetically engineered to imitate ECM. Furthermore, it can, reversibly, thermally interconvert between its polymeric and monomeric forms even when chemically crosslinked within a hydrogel network. It is demonstrated that this meltable feature of Caf1 hydrogels can be utilized to encapsulate neonatal human dermal fibroblasts at a range of cell densities (2 × 105 -2 × 106  cells mL-1 of hydrogel) avoiding issues with chemical cytotoxicity. These hydrogels supported cell 3D culture for up to 21 d, successfully inducing cellular functions such as proliferation and migration. This work is significant because it further highlights the potential of simple, robust, Caf1-based hydrogels as a cell culture platform.

Fetal Undernutrition Modifies Vascular RAS Balance Enhancing Oxidative Damage and Contributing to Remodeling.

Fetal stress is known to increase susceptibility to cardiometabolic diseases and hypertension in adult age in a process known as fetal programming. This study investigated the relationship between vascular RAS, oxidative damage and remodeling in fetal programming. Six-month old Sprague-Dawley offspring from mothers that were fed ad libitum (CONTROL) or with 50% intake during the second half of gestation (maternal undernutrition, MUN) were used. qPCR or immunohistochemistry were used to obtain the expression of receptors and enzymes. Plasma levels of carbonyls were measured by spectrophotometry. In mesenteric arteries from MUN rats we detected an upregulation of ACE, ACE2, AT1 receptors and NADPH oxidase, and lower expression of AT2, Mas and MrgD receptors compared to CONTROL. Systolic and diastolic blood pressure and plasma levels of carbonyls were higher in MUN than in CONTROL. Vascular morphology evidenced an increased media/lumen ratio and adventitia/lumen ratio, and more connective tissue in MUN compared to CONTROL. In conclusion, fetal undernutrition indices RAS alterations and oxidative damage which may contribute to the remodeling of mesenteric arteries, and increase the risk of adverse cardiovascular events and hypertension.

Genetic characterization of Chikungunya virus circulating in individuals from Paraná, Brazil.

Phylogenetic analysis carried out in several Brazilian regions shows the circulation of the Asian and East-Central South African (ECSA) Chikungunya virus (CHIKV) genotypes in the country. Until now, there are no genetic studies about CHIKV strains circulating in the South region. In this study, we sequenced 5 new partial sequences of the CHIKV Envelope 1 gene from strains detected in Paraná state during the years 2016-2017. Maximum likelihood and neighbor-joining trees grouped all sequences in Brazilian branches within ECSA genotype and comparative analysis did not show E1-A226V mutation. However, we identified E1-K211T amino acid substitution in a sample demonstrating the dispersion of mutant strains in the country.

Photoprotective action, anti-oxidant activity, and toxicity of aqueous extracts of Campomanesia sessiliflora O. Berg / Acción fotoprotectora, actividad antioxidante y toxicidad de extractos acuosos de Campomanesia sessiliflora O. Berg / Ação fotoprotetora, atividade antioxidante e toxicidade de extratos aquosos de Campomanesia sessiliflora O. Berg

Abstract Campomanesia sessiliflora O. Berg is a medicinal plant that is object of very few studies in the literature. In this context, the antioxidant activity, sun protection factor (SPF) and toxicity in Artemiasalina Leachs were analysed, as well as the contents of phenolic compounds, flavonoids and tannins in aqueous extracts prepared by infusion and maceration of C. sessiliflora leaves. Maceration showed higher levels of phenolic compounds and flavonoids regarding infusion and the two samples had the same tannin content. The LD50 was similar for the extracts, both were considered as low toxicity in the test with A. salina. Infusion presented a SPF of 9.98, while maceration presented a SPF of 6.74. Maceration presented better contents of secondary metabolites and antioxidant activity and infusion presented a better SPF. The extracts have the potential of incorporation into multifunctional products.

Resumen Campomanesia sessiliflora O. Berg es una planta medicinal que tiene pocos estudios en la literatura. En este contexto, se analizó la actividad antioxidante, factor de protección solar (FPS) y toxicidad en lixiviados de Artemia salina, así como el contenido de compuestos fenólicos, flavonoides y taninos en extractos acuosos preparados por infusión y maceración de hojas de C. sessiliflora. La maceración mostró niveles más altos de compuestos fenólicos y flavonoides, en relación con la infusión, y las dos muestras tuvieron el mismo contenido de taninos. La DL50 fue similar para los extractos, considerándose ambas muestras de baja toxicidad en el ensayo con A. salina. La infusión presentó un FPS de 9,98, mientras que la maceración tuvo un FPS de 6,74. La maceración mostró niveles más altos de metabolitos secundarios y actividad antioxidante y la infusión mostró un mejor FPS. Los extractos muestran potencial para incorporarse a productos multifuncionales.

Resumo Campomanesia sessiliflora O. Berg é uma planta medicinal que apresenta poucos estudos na literatura. Neste contexto, foram analisados a atividade antioxidante, fator de proteção solar (FPS) e toxicidade em Artemia salina Leachs, assim como os teores de compostos fenólicos, flavonoides e taninos dos extratos aquosos preparados por infusão e maceração das folhas de C. sessiliflora. A maceração apresentou maior teores de compostos fenólicos e flavonoides em relação a infusão e as duas amostras apresentaram o mesmo teor de taninos. O DL50 foi semelhante para os extratos, ambas amostras sendo consideradas como baixa toxicidade no ensaio com A. salina. A infusão apresentou FPS de 9,98, enquanto que a maceração o FPS foi de 6,74. A maceração apresentou maiores teores de metabólitos secundários e atividade antioxidante e a infusão apresentou melhor FPS. Os extratos apresentam potencial para a incorporação em produtos multifuncionais.

Mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force.

The hypoxia-inducible nuclear-encoded mitochondrial protein NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) has been demonstrated to decrease oxidative phosphorylation and production of reactive oxygen species in neonatal cardiomyocytes, brain tissue and hypoxic domains of cancer cells. Prolonged local hypoxia can negatively affect skeletal muscle size and tissue oxidative capacity. Although skeletal muscle is a mitochondrial rich, oxygen sensitive tissue, the role of NDUFA4L2 in skeletal muscle has not previously been investigated. Here we ectopically expressed NDUFA4L2 in mouse skeletal muscles using adenovirus-mediated expression and in vivo electroporation. Moreover, femoral artery ligation (FAL) was used as a model of peripheral vascular disease to induce hind limb ischemia and muscle damage. Ectopic NDUFA4L2 expression resulted in reduced mitochondrial respiration and reactive oxygen species followed by lowered AMP, ADP, ATP, and NAD+ levels without affecting the overall protein content of the mitochondrial electron transport chain. Furthermore, ectopically expressed NDUFA4L2 caused a ~20% reduction in muscle mass that resulted in weaker muscles. The loss of muscle mass was associated with increased gene expression of atrogenes MurF1 and Mul1, and apoptotic genes caspase 3 and Bax. Finally, we showed that NDUFA4L2 was induced by FAL and that the Ndufa4l2 mRNA expression correlated with the reduced capacity of the muscle to generate force after the ischemic insult. These results show, for the first time, that mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force. Specifically, induced NDUFA4L2 reduces mitochondrial activity leading to lower levels of important intramuscular metabolites, including adenine nucleotides and NAD+ , which are hallmarks of mitochondrial dysfunction and hence shows that dysfunctional mitochondrial activity may drive muscle wasting.

Endurance exercise training-responsive miR-19b-3p improves skeletal muscle glucose metabolism.

Skeletal muscle is a highly adaptable tissue and remodels in response to exercise training. Using short RNA sequencing, we determine the miRNA profile of skeletal muscle from healthy male volunteers before and after a 14-day aerobic exercise training regime. Among the exercise training-responsive miRNAs identified, miR-19b-3p was selected for further validation. Overexpression of miR-19b-3p in human skeletal muscle cells increases insulin signaling, glucose uptake, and maximal oxygen consumption, recapitulating the adaptive response to aerobic exercise training. Overexpression of miR-19b-3p in mouse flexor digitorum brevis muscle enhances contraction-induced glucose uptake, indicating that miR-19b-3p exerts control on exercise training-induced adaptations in skeletal muscle. Potential targets of miR-19b-3p that are reduced after aerobic exercise training include KIF13A, MAPK6, RNF11, and VPS37A. Amongst these, RNF11 silencing potentiates glucose uptake in human skeletal muscle cells. Collectively, we identify miR-19b-3p as an aerobic exercise training-induced miRNA that regulates skeletal muscle glucose metabolism.

Effects of Tryptophan Supplementation and Exercise on the Fate of Kynurenine Metabolites in Mice and Humans.

The kynurenine pathway of tryptophan (TRP) degradation (KP) generates metabolites with effects on metabolism, immunity, and mental health. Endurance exercise training can change KP metabolites by changing the levels of KP enzymes in skeletal muscle. This leads to a metabolite pattern that favors energy expenditure and an anti-inflammatory immune cell profile and reduces neurotoxic metabolites. Here, we aimed to understand if TRP supplementation in untrained vs. trained subjects affects KP metabolite levels and biological effects. Our data show that chronic TRP supplementation in mice increases all KP metabolites in circulation, and that exercise reduces the neurotoxic branch of the pathway. However, in addition to increasing wheel running, we did not observe other effects of TRP supplementation on training adaptations, energy metabolism or behavior in mice. A similar increase in KP metabolites was seen in trained vs. untrained human volunteers that took a TRP drink while performing a bout of aerobic exercise. With this acute TRP administration, TRP and KYN were higher in the trained vs. the untrained group. Considering the many biological effects of the KP, which can lead to beneficial or deleterious effects to health, our data encourage future studies of the crosstalk between TRP supplementation and physical exercise.

Interaction between the Renin-Angiotensin System and Enteric Neurotransmission Contributes to Colonic Dysmotility in the TNBS-Induced Model of Colitis.

Angiotensin II (Ang II) regulates colon contraction, acting not only directly on smooth muscle but also indirectly, interfering with myenteric neuromodulation mediated by the activation of AT1 /AT2 receptors. In this article, we aimed to explore which mediators and cells were involved in Ang II-mediated colonic contraction in the TNBS-induced rat model of colitis. The contractile responses to Ang II were evaluated in distinct regions of the colon of control animals or animals with colitis in the absence and presence of different antagonists/inhibitors. Endogenous levels of Ang II in the colon were assessed by ELISA and the number of AT1/AT2 receptors by qPCR. Ang II caused AT1 receptor-mediated colonic contraction that was markedly decreased along the colons of TNBS-induced rats, consistent with reduced AT1 mRNA expression. However, the effect mediated by Ang II is much more intricate, involving (in addition to smooth muscle cells and nerve terminals) ICC and EGC, which communicate by releasing ACh and NO in a complex mechanism that changes colitis, unveiling new therapeutic targets.

Neuronal cell-based high-throughput screen for enhancers of mitochondrial function reveals luteolin as a modulator of mitochondria-endoplasmic reticulum coupling.

BACKGROUND: Mitochondrial dysfunction is a common feature of aging, neurodegeneration, and metabolic diseases. Hence, mitotherapeutics may be valuable disease modifiers for a large number of conditions. In this study, we have set up a large-scale screening platform for mitochondrial-based modulators with promising therapeutic potential. RESULTS: Using differentiated human neuroblastoma cells, we screened 1200 FDA-approved compounds and identified 61 molecules that significantly increased cellular ATP without any cytotoxic effect. Following dose response curve-dependent selection, we identified the flavonoid luteolin as a primary hit. Further validation in neuronal models indicated that luteolin increased mitochondrial respiration in primary neurons, despite not affecting mitochondrial mass, structure, or mitochondria-derived reactive oxygen species. However, we found that luteolin increased contacts between mitochondria and endoplasmic reticulum (ER), contributing to increased mitochondrial calcium (Ca2+) and Ca2+-dependent pyruvate dehydrogenase activity. This signaling pathway likely contributed to the observed effect of luteolin on enhanced mitochondrial complexes I and II activities. Importantly, we observed that increased mitochondrial functions were dependent on the activity of ER Ca2+-releasing channels inositol 1,4,5-trisphosphate receptors (IP3Rs) both in neurons and in isolated synaptosomes. Additionally, luteolin treatment improved mitochondrial and locomotory activities in primary neurons and Caenorhabditis elegans expressing an expanded polyglutamine tract of the huntingtin protein. CONCLUSION: We provide a new screening platform for drug discovery validated in vitro and ex vivo. In addition, we describe a novel mechanism through which luteolin modulates mitochondrial activity in neuronal models with potential therapeutic validity for treatment of a variety of human diseases.