Trophic stimulation

Microplastics (MPs) and fluoxetine are ubiquitous emerging pollutants in aquatic environments that may interact with each other due to the carrier effects of MPs, posing unpredictable risks to non-target organisms. However, limited studies have focused on the carrier effects of MPs in the aquatic food chain. This study evaluated the influences of polystyrene MPs on the trophic transfer and biotoxicity of fluoxetine in a simple food chain composed of brine shrimp (Artemia nauplii) and zebrafish (Danio rerio)...

PURPOSE: To determine whether combination of topical ripasudil and brimonidine has more effective neuroprotection on retinal ganglion cells (RGCs) following injury to axons composing the optic nerve. METHODS: Topical ripasudil, brimonidine, or mixture of both drugs were administered to adult mice after optic nerve injury (ONI). The influence of drug conditions on RGC health were evaluated by the quantifications of surviving RGCs, phosphorylated p38 mitogen-activated protein kinase (phospho-p38), and expressions of trophic factors and proinflammatory mediators in the retina...

The mitochondrial translocator protein 18 kDa (TSPO) has been linked to functions from steroidogenesis to regulation of cellular metabolism and is an attractive therapeutic target for chronic CNS inflammation. Studies in Leydig cells and microglia indicate that TSPO function may vary between cells depending on their specialized roles. Astrocytes are critical for providing trophic and metabolic support in the brain. Recent work has highlighted that TSPO expression increases in astrocytes under inflamed conditions and may drive astrocyte reactivity...

Microbial communities are not only shaped by the diversity of microorganisms and their individual metabolic potential, but also by the vast amount of intra- and interspecies interactions that can occur pairwise interactions among microorganisms, we suggest that more attention should be drawn towards the effects on the entire microbiome that emerge from individual interactions between community members. The production of certain metabolites that can be tied to a specific microbe-microbe interaction might subsequently influence the physicochemical parameters of the habitat, stimulate a change in the trophic network of the community or create new micro-habitats through the formation of biofilms, similar to the production of antimicrobial substances which might negatively affect only one microorganism but cause a ripple effect on the abundance of other community members...

Cholesterol, an essential and versatile lipid, is the precursor substrate for the biosynthesis of steroid hormones, and a key structural and functional component of organelle membranes in eukaryotic cells. Consequently, the framework of steroidogenesis across main steroidogenic cell types is built around cholesterol, including its cellular uptake, mobilization from intracellular storage, and finally, its transport to the mitochondria where steroidogenesis begins. This setup, which is controlled by different trophic hormones in their respective target tissues, allows steroidogenic cells to meet their steroidogenic need of cholesterol effectively without impinging on the basic need for organelle membranes and their functions...

Extracellular vesicles (EVs) from cultured cells or bodily fluids have been demonstrated to show therapeutic value following myocardial infarction. However, challenges in donor variation, EV generation and isolation methods, and material availability have hindered their therapeutic use. Here, we show that human clinical-grade platelet concentrates from a blood establishment can be used to rapidly generate high concentrations of high purity EVs from sero-converted platelet lysate (SCPL-EVs) with minimal processing, using size-exclusion chromatography...

Resistance exercise (RE) training and pharmacological stimulation of β2 -Adrenoceptors (β2 -ARs) alone can promote muscle hypertrophy and prevent muscle atrophy. Although the activation of the sympathetic nervous system (SNS) is a well-established response during RE, the physiological contribution of the endogenous catecholamines and β2 -ARs to the RE-induced changes on skeletal muscle protein metabolism remains unclear. This study investigated the effects of the β2 -ARs blockade on the acute molecular responses induced by a single bout of RE in rodent skeletal muscles...

Microplastics (MPs) are pollutants of global concern, and bioaccumulation determines their biological effects. Although microorganisms form a large fraction of our ecosystem's biomass and are important in biogeochemical cycling, their accumulation of MPs has never been confirmed in natural waters because current tools for field biological samples can detect only MPs > 10 μm. Here, we show that stimulated Raman scattering microscopy (SRS) can image and quantify the bioaccumulation of small MPs (<10 μm) in protozoa...

The impoundment of rivers by dams has significantly modified sedimentation patterns and trophic structures. As a result, the algal-derived organic matter (OM), as opposed to terrestrial-derived OM, plays an increasingly important role along the river-reservoir gradient. This study utilized water-sediment microcosms to explore the impacts of allochthonous and autochthonous OM deposition on benthic nutrient dynamics mediated by microbial food webs. Our results revealed that OM addition led to increased fluxes of NH4 + and CO2 , with the highest flux induced by cyanobacteria OM, followed by diatom and allochthonous OM...

Fire can lead to transitions between forest and grassland ecosystems and trigger positive feedbacks to climate warming by releasing CO2 into the atmosphere. Climate change is projected to increase the prevalence and severity of wildfires. However, fire effects on the fate and impact of terrestrial organic matter (i.e., terrestrial subsidies) in aquatic ecosystems are unclear. Here, we performed a gradient design experiment in freshwater pond mesocosms adding 15 different amounts of burned or unburned plant detritus and tracking the chronology of detritus effects at 10, 31, 59, and 89 days...

Predators have a key role in structuring ecosystems1-4 . However, predator loss is accelerating globally4-6 , and predator mass-mortality events7 (MMEs)-rapid large-scale die-offs-are now emblematic of the Anthropocene epoch6 . Owing to their rare and unpredictable nature7 , we lack an understanding of how MMEs immediately impact ecosystems. Past predator-removal studies2,3 may be insufficient to understand the ecological consequences of MMEs because, in nature, dead predators decompose in situ and generate a resource pulse8 , which could alter ensuing ecosystem dynamics by temporarily enhancing productivity...

Stimulation of neoosteogenesis is the main mechanism of osseointegration during installation of dental implants, bone tissue recession, and alveolar process augmentation in adentia. In experiments on miniature pigs, we used the technology of two-stage splitting of the ridge of the alveolar process of the mandible in combination with a xenograft that was placed between the fragments of the split bone plate. The morphology of the reparative process and the distribution of osteogenic differentiation markers in the compact and trabecular bone of the alveolar crest were studied...

Elucidating the responses of soil microbial functional groups to changes in stand density is crucial for understanding the sustainability of forest development. In this study, we obtained soil samples from Robinia pseudoacacia plantations of three different stand densities (low, middle, and high densities of 750, 1125, and 1550 trees ha-1 , respectively) in the hilly and gully region of the Loess Plateau, China. We sought to determine the effects of stand density on the structure of soil microbial functional groups...

Neurofibromatosis type 1 (NF1) is an inherited multisystem disorder that affects one in 2500 to one in 5000 people. Neurofibromas are the second-most common benign peripheral nerve sheath tumors arising from Schwann cells and are associated with neurofibromatosis. Chronic pain and opioid use is elevated in patients with NF1 when neurofibromas are associated with sensory nerves. Surgical excision is the primary treatment of neurofibromas when they become large, malignant, or painful, but they are associated with high rates of recurrence...

Chronic skin wounds represent a prominent etiological factor in the occurrence of non-traumatic foot amputations on a global scale and pose a substantial threat to the patient's well-being and mortality in the absence of effective treatment strategies. There exists a subset of patients that exhibit an insufficient response to different treatment options, comprising antibiotics, dressings, gauze bandages, debridement, rehabilitation, collagen patch, and vacuum-assisted closure. In this patient group, distinct treatment strategies emerge before surgery and amputation...

Glial-cell line derived neurotrophic factor (GDNF) bound to its co-receptor GFRα1 stimulates the RET receptor tyrosine kinase, promoting neuronal survival and neuroprotection. The GDNF-GFRα1 complex also supports synaptic cell adhesion independently of RET. Here, we describe the structure of a decameric GDNF-GFRα1 assembly determined by crystallography and electron microscopy, revealing two GFRα1 pentamers bridged by five GDNF dimers. We reconsitituted the assembly between adhering liposomes and used cryo-electron tomography to visualize how the complex fulfils its membrane adhesion function...

Natural infochemicals may largely affect the trophic transfer of microplastics (MPs) in ecosystems but such infochemical effect and mechanisms are poorly understood. Here, a daphnids-zebrafish freshwater microcosm was designed to elucidate whether and how an algae-derived infochemical, dimethylsulfoniopropionate (DMSP), affects the ingestion and transfer of MPs. Daphnids fast accumulated DMSP and MPs from water, and DMSP in daphnids was mainly enriched from the DMSP in water but not from MPs. DMSP did not change the MP ingestion by daphnids...

Although pharmaceuticals are increasingly detected in abiotic matrices in the Arctic, the accumulation of drugs in the resident biota and trophic transfer have not been yet examined. This study investigated the behaviour of several pharmaceuticals in the rocky-bottom, macrobenthic food web in the coastal zone of Isfjorden (western Spitsbergen) using stable isotope analyses (SIA) coupled with liquid chromatography-mass spectrometry (LC-MS/MS). Across 16 macroalgal and invertebrate species the highest average concentration was measured for ciprofloxacin (CIP) (on average 60...

Excessive nitrogen (N) loading poses a substantial risk to soil biodiversity and disrupts carbon (C) flows within the soil food web. Intercropping with legumes is often considered a sustainable way to maintain soil N availability and mitigate the associated detrimental effects. However, it remains unclear whether and how legume crops restore energetic attenuation caused by N loading within the soil food web. Here, we conducted a two-year field experiment using randomized block design in a subtropic Camellia oleifera plantation with high wet N deposition...

Submerged macrophytes play crucial roles in maintaining the stability of clear-water states in shallow lakes. Recent stable isotope studies have shown that crustacean zooplankton can utilize submerged macrophyte carbon, but macrophytes alone cannot support the growth and reproduction of such grazers, being deficient in highly unsaturated fatty acids (HUFA). We hypothesized that flagellates feeding on macrophytes can synthesize HUFA and thereby support crustacean zooplankton. To test this hypothesis, we conducted a feeding experiment in which Daphnia magna were provided with a diet of submerged macrophyte Hydrilla verticillata detritus which had been degraded by lake microbes...