Fungal hypaphorine reduces growth and induces cytosolic calcium increase in root hairs of Eucalyptus globulus

Early Prediction of Septic Shock in Emergency Department Using Serum Metabolites

Early recognition of septic shock is crucial for improving clinical management and patient outcomes, especially in the emergency department (ED). This study conducted serum metabolomic profiling on ED patients diagnosed with septic shock (n = 32) and those without septic shock (n = 92) using a high-resolution mass spectrometer. By implementing a supervised machine learning algorithm, a prediction model based on a panel of metabolites achieved an accuracy of 87.8%. Notably, when employed on a low-resolution instrument, the model maintained its predictive performance with an accuracy of 84.2%. These results demonstrate the potential of metabolite-based algorithms to identify patients at high risk of septic shock. Our proposed workflow aims to optimize risk assessment and streamline clinical management processes in the ED, holding promise as an efficient routine test to promote timely intensive interventions and reduce septic shock mortality.

Hypaphorine exerts anti-inflammatory effects in sepsis induced acute lung injury via modulating DUSP1/p38/JNK pathway

Sepsis is a systemic inflammatory response syndrome attributed to infection, while sepsis-induced acute lung injury (ALI) has high morbidity and mortality. Here, we aimed to explore the specific mechanism of hypaphorine's anti-inflammatory effects in ALI. Lipopolysaccharide (LPS) was adopted to construct ALI model both in vivo and in vitro. BEAS-2B cell viability and apoptosis was testified by the MTT assay and flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to examine the expression of proinflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-18), and Western blot was adopted to examine the expression of the apoptosis-related proteins (Bax, Bcl2, and Caspase3) and the DUSP1/p38/JNK signaling pathway. At the same time, lung injury score, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were monitored. The dry/wet weight method was used to examine lung edema, and the total protein content in BALF was determined to test pulmonary vascular permeability. As the data suggested, hypaphorine inhibited the LPS-mediated apoptosis of alveolar epithelial cells. What is more, hypaphorine attenuated the expression of inflammatory factors (IL-1β, IL-6, TNF-α, and IL-18) and inactivated the p38/JNK signaling pathway through upregulating DUSP1 in a dose-dependent manner. Meanwhile, DUSP1 knockdown weakened the anti-inflammatory effect of hypaphorine on LPS-mediated lung injury. Furthermore, hypaphorine also relieved LPS induced ALI in rats with anti-inflammatory effects. Taken together, hypaphorine prevented LPS-mediated ALI and proinflammatory response via inactivating the p38/JNK signaling pathway by upregulating DUSP1.

Hypaphorine, an Indole Alkaloid Isolated from Caragana korshinskii Kom., Inhibites 3T3-L1 Adipocyte Differentiation and Improves Insulin Sensitivity in Vitro

Obesity, a major health problem worldwide, is a complex multifactorial chronic disease that increases the risk for insulin resistance, type 2 diabetes, coronary heart disease, and hypertension. In this study, we assessed methods to isolate hypaphorine, a potent drug candidate for obesity and insulin resistance. Semi-preparative reversed-phase liquid chromatography (semi-preparative RPLC) was established as a method to separate three compounds, adenosine, l-tryptophan, and hypaphorine, from the crude extracts of Caragana korshinskii Kom. Due to its specific chemical structure, the effect of hypaphorine on differentiation and dexamethasone (DXM) induced insulin resistance of 3T3-L1 cells was investigated. The structures of the three compounds were confirmed by UV, ¹ H-NMR, and ¹³ C-NMR analysis and compared with published data. The activity results indicated that hypaphorine prevented the differentiation of 3T3-L1 preadipocytes into adipocytes by down-regulating hormone-stimulated protein expression of peroxisome proliferator activated receptor γ (PPARγ) and CCAAT/enhancer binding protein (C/EBPα), and their downstream targets, sterol regulatory element binding protein 1 c (SREBP1c) and fatty acid synthase (FAS). Hypaphorine also alleviated DXM-induced insulin resistance in differentiated 3T3-L1 adipocytes via increasing the phosphorylation level of Akt2, a key protein in the insulin signaling pathway. Taken together, we suggest that the method can be applied to large-scale extraction and large-quantity preparation of hypaphorine for treatment of obesity and insulin resistance.

6-bromohypaphorine from marine nudibranch mollusk Hermissenda crassicornis is an agonist of human α7 nicotinic acetylcholine receptor

6-Bromohypaphorine (6-BHP) has been isolated from the marine sponges Pachymatisma johnstoni, Aplysina sp., and the tunicate Aplidium conicum, but data on its biological activity were not available. For the nudibranch mollusk Hermissenda crassicornis no endogenous compounds were known, and here we describe the isolation of 6-BHP from this mollusk and its effects on different nicotinic acetylcholine receptors (nAChR). Two-electrode voltage-clamp experiments on the chimeric α7 nAChR (built of chicken α7 ligand-binding and glycine receptor transmembrane domains) or on rat α4β2 nAChR expressed in Xenopus oocytes revealed no action of 6-BHP. However, in radioligand analysis, 6-BHP competed with radioiodinated α-bungarotoxin for binding to human α7 nAChR expressed in GH4C1 cells (IC50 23 ± 1 μM), but showed no competition on muscle-type nAChR from Torpedo californica. In Ca2+-imaging experiments on the human α7 nAChR expressed in the Neuro2a cells, 6-BHP in the presence of PNU120596 behaved as an agonist (EC50 ~80 μM). To the best of our knowledge, 6-BHP is the first low-molecular weight compound from marine source which is an agonist of the nAChR subtype. This may have physiological importance because H. crassicornis, with its simple and tractable nervous system, is a convenient model system for studying the learning and memory processes.

Calcium imaging perspectives in plants

The calcium ion (Ca²⁺) is a versatile intracellular messenger. It provides dynamic regulation of a vast array of gene transcriptions, protein kinases, transcription factors and other complex downstream signaling cascades. For the past six decades, intracellular Ca²⁺ concentration has been significantly studied and still many studies are under way. Our understanding of Ca²⁺ signaling and the corresponding physiological phenomenon is growing exponentially. Here we focus on the improvements made in the development of probes used for Ca²⁺ imaging and expanding the application of Ca²⁺ imaging in plant science research.

Calcium oxalate crystals in eucalypt ectomycorrhizae: morphochemical characterization

Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDS) microprobe analysis. The predominant forms of crystals were crystal sand (granules) and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants.

Indole derivative production by the root endophyte Piriformospora indica is not required for growth promotion but for biotrophic colonization of barley roots

Beneficial effects elicited by the root endophyte Piriformospora indica are widely known, but the mechanism by which these are achieved is still unclear. It is proposed that phytohormones produced by the fungal symbiont play a crucial role in the interaction with the plant roots. Biochemical analyses of the underlying biosynthetic pathways for auxin production have shown that, on tryptophan feeding, P. indica can produce the phytohormones indole-3-acetic acid (IAA) and indole-3-lactate (ILA) through the intermediate indole-3-pyruvic acid (IPA). Time course transcriptional analyses after exposure to tryptophan designated the piTam1 gene as a key player. A green fluorescence protein (GFP) reporter study and transcriptional analysis of colonized barley roots showed that piTam1 is induced during the biotrophic phase. Piriformospora indica strains in which the piTam1 gene was silenced via an RNA interference (RNAi) approach were compromised in IAA and ILA production and displayed reduced colonization of barley (Hordeum vulgare) roots in the biotrophic phase, but the elicitation of growth promotion was not affected compared with the wild-type situation. Our results suggest that IAA is involved in the establishment of biotrophy in P. indica-barley symbiosis and might represent a compatibility factor in this system.

Rapid tip growth: insights from pollen tubes

Pollen tubes extend rapidly in an oscillatory manner by the extreme form of polarized growth, tip growth, and provide an exciting system for studying the spatiotemporal control of polarized cell growth. The Rho-family ROP GTPase is a key signaling molecule in this growth control and is periodically activated at the apical plasma membrane to spatially define the apical growth region and temporally precede the burst of growth. The spatiotemporal dynamics of ROP GTPase is interconnected with actin dynamics and polar exocytosis that is required for tip-targeted membrane and wall expansion. Recent advances in the study of the mechanistic interlinks between ROP-centered signaling and spatiotemporal dynamics of cell membrane and wall remodeling will be discussed.

In vivo imaging of Ca2+, pH, and reactive oxygen species using fluorescent probes in plants

Changes in the levels of Ca(2+), pH, and reactive oxygen species (ROS) are recognized as key cellular regulators involved in diverse physiological and developmental processes in plants. Critical to understanding how they exert such widespread control is an appreciation of their spatial and temporal dynamics at levels from organ to organelle and from seconds to many hours. With appropriate controls, fluorescent sensors can provide a robust approach with which to quantify such changes in Ca(2+), pH, and ROS in real time, in vivo. The fluorescent cellular probes available for visualization split into two broad classes: (a) dyes and (b) an increasingly diverse set of genetically encoded sensors based around green fluorescent proteins (GFPs). The GFP probes in particular can be targeted to well-defined subcellular locales, offering the possibility of high-resolution mapping of these signals within the cell.

A pH signaling mechanism involved in the spatial distribution of calcium and anion fluxes in ectomycorrhizal roots

Mycorrhization is a typical example of a host-pathogen symbiotic interaction where the pathogen cell biology and the host immune response coevolved several functional links. Here, the role played by ion fluxes across the root concerning nutrient uptake, osmoregulation, growth and signaling events is addressed. An ion-selective vibrating probe system was used to determine the net fluxes of protons (H(+)), calcium (Ca(2+)) and anions (A(-)) along nonmycorrhizal and ectomycorrhizal (ECM) roots of Eucalyptus globulus colonized by Pisolithus sp. These data show that, from five root zones analyzed, the main effect of fungal colonization was localized to the elongation zone. Here, strong changes in ion dynamics and rhizosphere acidification capacity were observed. Additionally, ion fluxes exhibited periodic fluctuations. To verify whether these fluctuations corresponded to sustained oscillations, continuous wavelet time spectrum analysis was applied and it was determined that H(+) and A(-) fluxes from ECM roots had longer periods than nonmycorrhizal roots. By contrast, Ca(2+) oscillations were completely abolished following fungal interaction. These results are interpreted in the light of a working model in which nutrient uptake and stimulation of growth are mediated by ECM fungi and may be pH-dependent. Furthermore, the variations detected in ECM roots for H(+) and A(-) fluxes suggest a main contribution from the plant, while the results obtained for Ca(2+) point to a significant involvement of the fungus.