Pulling the strings on solid-to-liquid phase transitions in cell collectives.

Cell collectives must dynamically adapt to different biological contexts. For instance, in homeostatic conditions, epithelia must establish a barrier between body compartments and resist external stresses, while during development, wound healing or cancer invasion, these tissues undergo extensive remodeling. Using analogies from inert, passive materials, changes in cellular density, shape, rearrangements and/or migration were shown to result in collective transitions between solid and fluid states. However, what biological mechanisms govern these transitions remains an open question. In particular, the upstream signaling pathways and molecular effectors controlling the key physical axes determining tissue rheology and dynamics remain poorly understood. In this perspective, we focus on emerging evidence identifying the first biological signals determining the collective state of living tissues, with an emphasis on how these mechanisms are exploited for functionality across biological contexts.

In vitro anti-inflammatory activity and ameliorative effects on gastric ulcers of Licania rigida benth seed extract.

Licania rigida Benth., a Brazilian endemic plant, has been traditionally used for treating inflammation and stomach pain. This work investigates the anti-inflammatory and gastroprotective activities of the ethanolic extract from L. rigida seeds (EELr) by in vitro and in vivo methods. The phytochemical profile was determined and the in vitro antioxidant activity was investigated by radical scavenging and thiobarbituric acid reactive substances methods. The ovalbumin denaturation method was used with sodium diclofenac as standard for the in vitro anti-inflammatory activity assessment. Acetylsalicylic acid was used to induce gastric ulcers in male mice and then to evaluate the preventive and therapeutic gastroprotective effect of EELr, using omeprazole as the reference drug. The extract exhibited relevant amount of phenolic compounds and flavonoids, in particular, demonstrating in vitro antioxidant capacity. EELr was able to inhibit almost 60% of ovalbumin denaturation at a concentration considered low. It also prevented the decrease of biochemical markers for oxidative stress such as superoxide dismutase (SOD) and reduced glutathione (GSH) in the stomach and SOD and catalase (CAT) in the liver. EELr also significantly decreased the number of lesions as well as reduced the ulcerated area when used as therapy. The observed effect may be due to its phenolic compounds, such as chlorogenic acid, caffeic acid and tannins, as previously reported. EELr is a potential source of compounds with anti-inflammatory activity, protects the liver from oxidative damage and improves healing of aspirin-induced ulcers. This work contributes to the knowledge of L. rigida species.

Developmental mechanisms understood quantitatively.

Across developmental systems, quantitative and imaging-based approaches have provided unprecedented resolution of dynamic changes in gene regulation and cell fate specification, along with complex changes in tissue morphology. This has set the stage for a wealth of comprehensive theoretical models, parameterised by experimental data, able to reproduce key aspects of biological behaviour and jointly enabling a higher level of abstraction, going from the identification of the molecular components to understanding complex functional relationships between these components. Despite these successes, gaining a cross-scale understanding of developmental systems will require further collaboration between disciplines, from developmental biology to bioengineering, systems biology and biophysics. We highlight the exciting multi-disciplinary research discussed at The Company of Biologists workshop 'Fostering quantitative modelling and experimentation in Developmental Biology'.

A hydraulic feedback loop between mesendoderm cell migration and interstitial fluid relocalization promotes embryonic axis formation in zebrafish.

Interstitial fluid (IF) accumulation between embryonic cells is thought to be important for embryo patterning and morphogenesis. Here, we identify a positive mechanical feedback loop between cell migration and IF relocalization and find that it promotes embryonic axis formation during zebrafish gastrulation. We show that anterior axial mesendoderm (prechordal plate [ppl]) cells, moving in between the yolk cell and deep cell tissue to extend the embryonic axis, compress the overlying deep cell layer, thereby causing IF to flow from the deep cell layer to the boundary between the yolk cell and the deep cell layer, directly ahead of the advancing ppl. This IF relocalization, in turn, facilitates ppl cell protrusion formation and migration by opening up the space into which the ppl moves and, thereby, the ability of the ppl to trigger IF relocalization by pushing against the overlying deep cell layer. Thus, embryonic axis formation relies on a hydraulic feedback loop between cell migration and IF relocalization.

In vitro long-term culture of isolated ovine preantral follicles: Influence of ethanol on steroid production, oocyte meiotic resumption, and metabolomic profile.

Ethanol is used routinely to dilute cell culture media supplements with little or no water solubility. This study evaluates the effect of low concentration of ethanol on the follicular development, oocyte maturation, hormone production, gene expression, and metabolomics profile of spent culture medium after long-term culture of isolated ovine preantral follicles. For this, follicles were cultured for 18 days in α-Minimum Essential Medium+ alone (control treatment) or supplemented with 100 ng/mL recombinant bovine FSH (rbFSH treatment) or with 0.2%-v/v ethanol (ethanol treatment). Ethanol treatment increased the percentage of degenerated follicles and oocytes significantly, however, it showed the highest estradiol secretion. Also, the rate of meiosis resumption was higher in ethanol treatment than Control treatment. Ethanol treatment decreased the mRNA levels of B-cell lymphoma 2 (BCL2), BCL2 associated X, Aquaporin 3, Connexin 43, Inhibin Subunit Beta A, kit ligand, Heat Shock Protein (HSP A1A) significantly when compared to the Control treatment. However, mRNA levels of cytochrome P450 family 19, and FSH receptors were significantly higher in ethanol treatment than in the Control treatment. The levels of some metabolites, which are likely amino acids, lipids, an analog of Cyclic guanosine monophosphate, and a derivative of phosphoinositol phosphate metabolism, had higher relative concentrations in ethanol and rbFSH treatments than the Control treatment. In conclusion, ethanol addition augmented the follicular and oocyte degeneration rates but increased the estradiol production and the meiotic resumption. Furthermore, the follicular metabolomic profile was similar between ethanol and rbFSH treatments being both treatments; however, different from the Control treatment.

Leukocytes and albumin in canine leishmaniasis

Canine Leishmaniasis (CanL) is a multisystemic and chronic inflammatory disease characterized by nonspecific clinical manifestations. In CanL, inflammatory cells and chemical mediators released in response to the parasite play a role in disease development and progression. Alterations on hematological parameters have been documented in CanL. These changes can also be assessed in relation to systemic inflammation caused by this disease. The circulating leukocyte counting, such as neutrophils, as well as the albumin level, are considered direct indicators of an inflammatory host environment. Several studies point to the use of biomarkers on the assistance in diagnosis and prognosis of several canine pathologies. The present study investigated the Neutrophils to Lymphocyte Ratio (NLR), Albumin to Globulin Ratio (AGR), and Neutrophils to Albumin Ratio (NAR) on systemic inflammatory response induced by Canine Leishmaniasis (CanL). For this purpose, adult dogs with confirmed diagnosis to CanL were divided into symptomatic (SD, n = 33) and asymptomatic (AD, n = 20) dogs for L. infantum and control dogs (CD, n = 20). Routine hematological and biochemical parameters were determined in blood samples using a veterinary automatic hematology and biochemical analyzers. Asymptomatic dogs (AD) had a higher number of white blood cells and neutrophils (16.48 ± 4.93; 13.41 ± 3.60, respectively) in relation to symptomatic dogs (SD) (13.54 ± 5.13; 10.42 ± 3.69, respectively) (P = 0.015 and P < 0.0001, respectively). Neutrophils to Lymphocyte Ratio (NLR) was higher in dogs with leishmaniasis (9.45 ± 3.76) than in healthy dogs (3.39 ± 1.19) (P < 0.0001). Serum total proteins (STP) and globulins increased in CanL, while albumin and AGR decreased in CanL, when compared to CD and references values to canine species. Neutrophils to Albumin Ratio (NAR) was higher in AD and SD (5.02 ± 1.14; 4.79 ± 1.07, respectively) when compared to CD (2.36 ± 0.55) (P < 0.0001). As reported in scientific researches, dogs with Leishmaniasis present alterations in circulating cell counts. Based on these data, we decided to expand this information using the NLR as a parameter in an attempt to better clarify the changes in these cells in CanL. We observed that NLR was increased on CanL in relation to healthy dogs, which could be a consequence of relative neutrophilia rather than lymphopenia. Neutrophils to Lymphocyte Ratio (NLR) is a biomarker that conveys information about inflammatory conditions. An elevated NLR can reflect an upregulated innate immune response, since neutrophils are effector cells of innate immunity and are involved in several acute and chronic inflammatory processes. Albumin is an acute phase protein that is considered an immune-inflammatory biomarker, which can be found reduced systemically in progressive inflammatory response. Serum total proteins (STP) and globulins were increased in CanL. These data are already well documented in CanL, which serum globulins are mainly associated with the increase of acute phase proteins, cytokines, and increase of specific antibodies to Leishmania infantum. Our results showed neutrophilia with hypoalbuminemia in CanL. So, in an attempt to assess the relationship of these two available markers, we used NAR calculation in order to evaluate the changes induced by CanL. In this study NAR was higher in CanL when compared to control dogs. Thus, our data indicate that NLR and NAR could be used as biomarkers in veterinary medical clinics in order to assess inflammatory profile in CanL, mainly in asymptomatic dogs. These parameters obtained from routine blood tests might be useful as cost-effective, easily accessible and helpful markers in order to distinguish the inflammatory response intensity in CanL.(AU)

Zebrafish embryonic explants undergo genetically encoded self-assembly.

Embryonic stem cell cultures are thought to self-organize into embryoid bodies, able to undergo symmetry-breaking, germ layer specification and even morphogenesis. Yet, it is unclear how to reconcile this remarkable self-organization capacity with classical experiments demonstrating key roles for extrinsic biases by maternal factors and/or extraembryonic tissues in embryogenesis. Here, we show that zebrafish embryonic tissue explants, prepared prior to germ layer induction and lacking extraembryonic tissues, can specify all germ layers and form a seemingly complete mesendoderm anlage. Importantly, explant organization requires polarized inheritance of maternal factors from dorsal-marginal regions of the blastoderm. Moreover, induction of endoderm and head-mesoderm, which require peak Nodal-signaling levels, is highly variable in explants, reminiscent of embryos with reduced Nodal signals from the extraembryonic tissues. Together, these data suggest that zebrafish explants do not undergo bona fide self-organization, but rather display features of genetically encoded self-assembly, where intrinsic genetic programs control the emergence of order.

Toxicological effects of the rare earth element neodymium in Mytilus galloprovincialis.

The wide range of applications of rare earth elements (REE) is leading to their occurrence in worldwide aquatic environments. Among the most popular REE is Neodymium (Nd), being widely used in permanent magnets, lasers, and glass additives. Neodymium-iron-boron (NdFeB) magnets is the main application of Nd since they are used in electric motors, hard disk drives, speakers and generators for wind turbines. Recent studies have already evaluated the toxic potential of different REE, but no information is available on the effects of Nd towards marine bivalves. Thus, the present study evaluated the biochemical alterations caused by Nd in the mussel Mytilus galloprovincialis exposed to this element for 28 days. The results obtained clearly demonstrated that Nd was accumulated by mussels, leading to mussel's metabolic capacity increase and GLY expenditure, in an attempt to fuel up defense mechanisms. Antioxidant and biotransformation defenses were insufficient in the elimination of ROS excess, resulting from the presence of Nd and increased electron transport system activity, which caused cellular damages (measured by lipid peroxidation) and loss of redox balance (assessed by the ratio between reduced and oxidized glutathione). The results obtained clearly highlight the potential toxicity of REEs and, in particular of Nd, with impacts at cellular level, which may have consequences in mussel's survival, growth and reproduction, affecting mussel's population.

Zebrafish gastrulation: Putting fate in motion.

Gastrulation entails specification and formation of three embryonic germ layers-ectoderm, mesoderm and endoderm-thereby establishing the basis for the future body plan. In zebrafish embryos, germ layer specification occurs during blastula and early gastrula stages (Ho & Kimmel, 1993), a period when the main morphogenetic movements underlying gastrulation are initiated. Hence, the signals driving progenitor cell fate specification, such as Nodal ligands from the TGF-ß family, also play key roles in regulating germ layer progenitor cell segregation (Carmany-Rampey & Schier, 2001; David & Rosa, 2001; Feldman et al., 2000; Gritsman et al., 1999; Keller et al., 2008). In this review, we summarize and discuss the main signaling pathways involved in germ layer progenitor cell fate specification and segregation, specifically focusing on recent advances in understanding the interplay between mesoderm and endoderm specification and the internalization movements at the onset of zebrafish gastrulation.

Clinical outcomes of 28 cats 12-24 months after urethrostomy.

OBJECTIVES: The aim of this study was to evaluate and compare the long-term clinical outcomes and quality of life of cats having undergone perineal urethrostomy (PU) or prepubic urethrostomy (PPU). METHODS: This clinical study followed 28 cats (PU, n = 22; PPU, n = 6) that underwent a urethrostomy, with a minimum of 1 year postoperative follow-up. Medical records, pet owner surveys and urologic laboratory tests were used for assessment. Urologic laboratory tests included serum symmetric dimethylarginine (SDMA), serum creatinine, urinalysis, urine specific gravity (USG), urine protein:creatinine (UPC) ratio and urine culture. RESULTS: The main indications for urethrostomy were multiple catheterizations and PU stricture. The overall complication rates of PU and PPU were 31.8% and 83.3%, respectively. Recurrent urinary tract infection (UTI) and urine scald dermatitis were less frequent in PU than in PPU cats (UTI 22.7% vs 66.6%; dermatitis 4.5% vs 83.3%). Bacteriuria was present in 77.2% and 100% of PU and PPU cats, respectively. Owner satisfaction rates were excellent in 81.8% of PU and 33.3% of PPU cases. CONCLUSIONS AND RELEVANCE: A proportion of cats that underwent urethrostomy showed bacteriuria, recurrent UTIs and increased levels of SDMA. PPU is important as a salvage procedure; however, it should be limited to cases in which standard techniques for PU cannot be performed, owing to the potential for recurrent complications and lower owner satisfaction.

Impact of massage on goats on the human-animal relationship and parameters linked to physiological response / Impacto da massagem em cabras na relação homem-animal e parâmetros relacionados à resposta fisiológica

ABSTRACT: Considering the benefits that massage can promote, this research aimed to apply the stroking massage in five adult goats (G1-G5) assessed in group and individually for ten days. Parameters related to massage, immune system, physiology and behavior of goats were observed. There was only significant difference (P<0.05) regarding behavior expressed in the presence of the masseur in G4 and G5, between week 1 and 2. Most goats accepted massage, except G2, with greater demonstrations of positive than negative behavior towards the masseur. Therefore, stroking massage promoted positive interactions between the masseur and goats, and should be explored as an alternative method to those existing in improving the relationship between humans and farm animals.

RESUMO: Considerando os benefícios que a massagem pode promover, este trabalho teve como objetivo aplicar a massagem do tipo stroking em cinco cabras adultas (G1-G5) avaliadas em grupo e individualmente por dez dias. Parâmetros relacionados à massagem, sistema imunológico, fisiologia e comportamento das cabras foram observados. Houve apenas diferença significativa (P<0,05) em relação ao comportamento expresso na presença da massagista em G4 e G5, entre as semanas 1 e 2. A maioria das cabras aceitou a massagem, exceto G2, com maiores demonstrações de comportamentos positivos do que negativos direcionados à massagista. Portanto, a massagem do tipo stroking promoveu interações positivas entre a massagista e as cabras, devendo ser explorada como um método alternativo aos existentes na melhora da relação entre seres humanos e animais de produção.

Mechanical Force-Driven Adherens Junction Remodeling and Epithelial Dynamics.

During epithelial tissue development, repair, and homeostasis, adherens junctions (AJs) ensure intercellular adhesion and tissue integrity while allowing for cell and tissue dynamics. Mechanical forces play critical roles in AJs' composition and dynamics. Recent findings highlight that beyond a well-established role in reinforcing cell-cell adhesion, AJ mechanosensitivity promotes junctional remodeling and polarization, thereby regulating critical processes such as cell intercalation, division, and collective migration. Here, we provide an integrated view of mechanosensing mechanisms that regulate cell-cell contact composition, geometry, and integrity under tension and highlight pivotal roles for mechanosensitive AJ remodeling in preserving epithelial integrity and sustaining tissue dynamics.

Himatanthus drasticus (Apocynaceae) latex reduces oxidative stress and modulates CD4+, CD8+, FoxP3+ and HSP-60+ expressions in Sarcoma 180-bearing mice.

ETHNOPHARMACOLOGICAL RELEVANCE: In Brazil, latex of Himatanthus drasticus is used to treat inflammation, wound healing and cancer. The present study evaluated the antitumoral potential of H. drasticus latex (HdCL) in Sarcoma 180-bearing mice (S180). MATERIALS AND METHODS: HdCL was obtained in Crato-CE, Brazil. Qualitative phytochemicals assays, nuclear magnetic resonance (NMR) and microbiological analyzes were performed. Swiss mice were divided into six groups, according to tumor forms: 1) ascitic model, GI (Control; 0.9% saline), GII (S180asc) and GIII (S180asc/HdCL/14 days); 2) solid model, GIV (Control; 0.9% saline), GV (S180sol) and GVI (S180sol/HdCL/10 days). HdCL and 0.9% saline were administered at 0.2 mL, SID, by gavage, for 10 or 14 days. For ascitic model, 0.5 mL of S180 suspension (4×106 cells/mL) was inoculated intraperitoneally and for solid model, cells were inoculated subcutaneously (25 µL) on the right hind paw of mice. Blood samples were collected for hematological and oxidative stress evaluation. Thickness, volume and weight of paws were measured in solid model. After euthanasia, spleen, liver and kidney were collected in order to assess the relative organ weight. Tissue fragments of paws and popliteal lymph nodes (PLN) were analyzed by H&E and CD4+, CD8+, HSP-60+ and Foxp3+ immunohistochemistry. RESULTS: HdCL presented milky aspect and pinkish supernatant. Phenols, flavonols, flavanones, free steroids and cinnamoyl derivatives of lupeol, α-amyrin and ß-amyrin were detected at the phytochemistry analysis. HdCL did not alter the relative weight of organs, hematological parameters and volume of ascitic fluid recovered. In solid model, HdCL reduced (P < 0.05) paw volume, but did not altered thickness, paw weight and histological parameters. S180sol induced necrosis, metastasis and destruction of bone, cartilage and muscles. Bleeding, vessel congestion and oncocytes were observed in PLN. In paw, HdCL did not alter FoxP3+ and HSP-60+ expressions but reduced the CD4+ and CD8+ expressions, while at PLN, HdCL reduced the expressions of all markers. HdCL decreased (P < 0.05) serum levels of malondialdehyde in ascitic model. CONCLUSIONS: Treatment with HdCL reduced oxidative damage and modulated the expressions of CD4+, CD8+, FoxP3+and HSP-60+ in S180 solid tumor model, which can be associated to the presence of triterpenes, such as α-amyrin, ß-amyrin and lupeol cinnamate. Present data emphasizes the importance of immune system in cancer and highlights the evaluation of the pharmacological properties of plants used by population as phytoterapics.

Transmission of cytokinesis forces via E-cadherin dilution and actomyosin flows.

During epithelial cytokinesis, the remodelling of adhesive cell-cell contacts between the dividing cell and its neighbours has profound implications for the integrity, arrangement and morphogenesis of proliferative tissues. In both vertebrates and invertebrates, this remodelling requires the activity of non-muscle myosin II (MyoII) in the interphasic cells neighbouring the dividing cell. However, the mechanisms that coordinate cytokinesis and MyoII activity in the neighbours are unknown. Here we show that in the Drosophila notum epithelium, each cell division is associated with a mechanosensing and transmission event that controls MyoII dynamics in neighbouring cells. We find that the ring pulling forces promote local junction elongation, which results in local E-cadherin dilution at the ingressing adherens junction. In turn, the reduction in E-cadherin concentration and the contractility of the neighbouring cells promote self-organized actomyosin flows, ultimately leading to accumulation of MyoII at the base of the ingressing junction. Although force transduction has been extensively studied in the context of adherens junction reinforcement to stabilize adhesive cell-cell contacts, we propose an alternative mechanosensing mechanism that coordinates actomyosin dynamics between epithelial cells and sustains the remodelling of the adherens junction in response to mechanical forces.

Renal biochemistry variables and ultrasonographic imaging in healthy Squirrel monkeys (Saimiri collinsi).

BACKGROUND: The combined use of renal biochemistry and ultrasonographic imaging may improve the correct management of renal disease. Although renal disease is frequently observed in nonhuman primates, renal function markers have not yet been studied in Squirrel monkeys (Saimiri collinsi). OBJECTIVES: The aim of this study was to establish normal renal biochemistry variables and ultrasonographic features in Squirrel monkeys. MATERIAL AND METHODS: Renal biochemistry variables and ultrasonographic images were documented in 29 healthy Squirrel monkeys (15 males and 14 females). Urea, serum creatinine (SCr), and uric acid (UA) concentrations were measured by kinetic assay. Cystatin C (CysC) was analyzed by immunonephelometry. A multiple frequency linear array probe (5-12 MHz) was used for ultrasonographic imaging. The studied indicators of renal function were related to sex, age, and body mass. RESULTS: Serum creatinine was influenced by sex and body mass. Serum concentration of urea, UA, and CysC were not influenced by sex, age, and body mass. Ultrasonographic images provided accurate and comprehensive data for making clinical decisions for Squirrel monkeys. The total renal volume was only influenced by the body mass nested in sex and was positively correlated to body mass. Right renal volume was bigger than the left one. CONCLUSION: Normative standards for the renal evaluation, including biochemistry and ultrasonography, in the Squirrel monkey have been established correlated to age, sex, and body mass.

Unexpected effect of the vehicle (grain ethanol) of homeopathic FSH on the in vitro survival and development of isolated ovine preantral follicles.

The aims of this study were to investigate the effects of medium replacement system (experiment I) and of FSH presentations (homeopathic - FSH 6cH and allopathic FSH - rFSH; experiment II) on the in vitro development, hormone production and gene expression of isolated ovine preantral follicles cultured for 6 days. In experiment I, secondary follicles were cultured in the α-MEM+ supplemented with FSH 6cH (0.05 fg/ml) or recombinant bovine FSH (100 ng/ml) without/with daily medium addition. The homeopathic FSH treatments with/without medium addition improved (p < .05) follicular development compared to rFSH100 treatment without addition. FSH 6cH with addition showed the highest (p < .05) estradiol production. To verify whether the effects of homeopathic FSH were not due to its vehicle, experiment II was performed. The α-MEM+ was supplemented or not with alcohol (0.2% grain ethanol, v/v), FSH 6cH or rFSH100 with daily medium addition. Surprisingly, we found that all treatments improved follicular development compared to the α-MEM+ (p < .05). Moreover, homeopathic FSH was similar to the other treatments including its vehicle. In conclusion, its vehicle (ethanol) causes the effect of homeopathic FSH on in vitro development of isolated ovine preantral follicles.

Fruit as Potent Natural Antioxidants and Their Biological Effects.

The consumption of fruit has increased in the last 20 years, along with the growing recognition of its nutritional and protective values. Many of the benefits of a diet rich in fruit are attributed to the presence of different bioactive substances, such as vitamins, carotenoids and phenolic compounds. Flavanoids, a class of phenolic compounds, present particular antioxidant activity and thus provide protection against cellular damage caused by reactive oxygen species. Research suggests that an increased intake of plant foods is associated with a reduced incidence of chronic disease. There is currently a great deal of interest in the study of antioxidants, in particular due to the discovery of the damaging effects of free radicals to the body. Thus, this review aims to address the beneficial effects of the antioxidants present in fruits, on the neutralization of reactive species and the reduction of any damage they may cause.