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International Journal of Molecular... Aug 2023The apical dendrite of a cortical projection neuron (CPN) is generated from the leading process of the migrating neuron as the neuron completes migration. This...
The apical dendrite of a cortical projection neuron (CPN) is generated from the leading process of the migrating neuron as the neuron completes migration. This transformation occurs in the cortical marginal zone (MZ), a layer that contains the Cajal-Retzius neurons and their axonal projections. Cajal-Retzius neurons (CRNs) are well known for their critical role in secreting Reelin, a glycoprotein that controls dendritogenesis and cell positioning in many regions of the developing brain. In this study, we examine the possibility that CRNs in the MZ may provide additional signals to arriving CPNs, that may promote the maturation of CPNs and thus shape the development of the cortex. We use whole embryonic hemisphere explants and multiphoton microscopy to confirm that CRNs display intracellular calcium transients of <1-min duration and high amplitude during early corticogenesis. In contrast, developing CPNs do not show high-amplitude calcium transients, but instead show a steady increase in intracellular calcium that begins at the time of dendritic initiation, when the leading process of the migrating CPN is encountering the MZ. The possible existence of CRN to CPN communication was revealed by the application of veratridine, a sodium channel activator, which has been shown to preferentially stimulate more mature cells in the MZ at an early developmental time. Surprisingly, veratridine application also triggers large calcium transients in CPNs, which can be partially blocked by a cocktail of antagonists that block glutamate and glycine receptor activation. These findings outline a model in which CRN spontaneous activity triggers the release of glutamate and glycine, neurotransmitters that can trigger intracellular calcium elevations in CPNs. These elevations begin as CPNs initiate dendritogenesis and continue as waves in the post-migratory cells. Moreover, we show that the pharmacological blockade of glutamatergic signaling disrupts migration, while forced expression of a bacterial voltage-gated calcium channel (CavMr) in the migrating neurons promotes dendritic growth and migration arrest. The identification of CRN to CPN signaling during early development provides insight into the observation that many autism-linked genes encode synaptic proteins that, paradoxically, are expressed in the developing cortex well before the appearance of synapses and the establishment of functional circuits.
Topics: Calcium Signaling; Calcium; Veratridine; Neurons; Dendrites; Calcium, Dietary; Glutamic Acid
PubMed: 37629145
DOI: 10.3390/ijms241612965 -
Scientific Reports May 2023Veratrum (Melanthiaceae; Liliales) is a genus of perennial herbs known for the production of unique bioactive steroidal alkaloids. However, the biosynthesis of these...
Veratrum (Melanthiaceae; Liliales) is a genus of perennial herbs known for the production of unique bioactive steroidal alkaloids. However, the biosynthesis of these compounds is incompletely understood because many of the downstream enzymatic steps have yet to be resolved. RNA-Seq is a powerful method that can be used to identify candidate genes involved in metabolic pathways by comparing the transcriptomes of metabolically active tissues to controls lacking the pathway of interest. The root and leaf transcriptomes of wild Veratrum maackii and Veratrum nigrum plants were sequenced and 437,820 clean reads were assembled into 203,912 unigenes, 47.67% of which were annotated. We identified 235 differentially expressed unigenes potentially involved in the synthesis of steroidal alkaloids. Twenty unigenes, including new candidate cytochrome P450 monooxygenases and transcription factors, were selected for validation by quantitative real-time PCR. Most candidate genes were expressed at higher levels in roots than leaves but showed a consistent profile across both species. Among the 20 unigenes putatively involved in the synthesis of steroidal alkaloids, 14 were already known. We identified three new CYP450 candidates (CYP76A2, CYP76B6 and CYP76AH1) and three new transcription factor candidates (ERF1A, bHLH13 and bHLH66). We propose that ERF1A, CYP90G1-1 and CYP76AH1 are specifically involved in the key steps of steroidal alkaloid biosynthesis in V. maackii roots. Our data represent the first cross-species analysis of steroidal alkaloid biosynthesis in the genus Veratrum and indicate that the metabolic properties of V. maackii and V. nigrum are broadly conserved despite their distinct alkaloid profiles.
Topics: Veratrum; Transcriptome; Alkaloids; Gene Expression Profiling; Veratrum Alkaloids; Steroids; Cytochrome P-450 Enzyme System
PubMed: 37211560
DOI: 10.1038/s41598-023-35429-5 -
Bioorganic & Medicinal Chemistry Apr 2023Cyclopamine (1), the teratogenic steroidal alkaloid isolated from corn lily (Veratrum californicum), has recently gained renewed interest due to its anticancer...
Cyclopamine (1), the teratogenic steroidal alkaloid isolated from corn lily (Veratrum californicum), has recently gained renewed interest due to its anticancer potential, that has been translated into the FDA approval of three Hedgehog (Hh) pathway inhibiting antitumor drugs. A chemical analysis of mother liquors obtained from crystallization of cyclopamine, extracted from roots and rhizomes of V. californicum, resulted in the isolation of two unprecedented cyclopamine analogues, 18-hydroxycyclopamine (2) and 24R-hydroxycyclopamine (3), the first compounds of this class to show modifications on rings D-F. The stereostructures of these new natural compounds have been established based on a detailed MS and 1D/2D NMR investigation. The isolated compounds were evaluated with the dual-luciferase bioassay for their inhibition of the hedgehog pathway in comparison to cyclopamine, providing new insights into the structure-activity relationships for this class of compounds.
Topics: Veratrum; Hedgehog Proteins; Veratrum Alkaloids; Alkaloids
PubMed: 37001245
DOI: 10.1016/j.bmc.2023.117265 -
Cells Mar 2023Glioblastoma (GBM) is a primary brain tumor of unknown etiology. It is extremely aggressive, incurable and has a short average survival time for patients. Therefore,...
Glioblastoma (GBM) is a primary brain tumor of unknown etiology. It is extremely aggressive, incurable and has a short average survival time for patients. Therefore, understanding the precise molecular mechanisms of this diseases is essential to establish effective treatments. In this study, we cloned and sequenced a splice variant of the hydroxysteroid 11-β dehydrogenase 1 like gene () and named it HSD11B1L-181. HSD11 B1L-181 was specifically expressed only in GBM cells. Overexpression of this variant can significantly promote the proliferation, migration and invasion of GBM cells. Knockdown of HSD11B1L-181 expression inhibited the oncogenic potential of GBM cells. Furthermore, we identified the direct interaction of parkin with HSD11B1L-181 by screening the GBM cDNA expression library via yeast two-hybrid. Parkin is an RBR E3 ubiquitin ligase whose mutations are associated with tumorigenesis. Small interfering RNA treatment of parkin enhanced the proliferative, migratory and invasive abilities of GBM. Finally, we found that the alkaloid peiminine from the bulbs of Miq blocks the interaction between HSD11B1L-181 and parkin, thereby lessening carcinogenesis of GBM. We further confirmed the potential of peiminine to prevent GBM in cellular, ectopic and orthotopic xenograft mouse models. Taken together, these findings not only provide insight into GBM, but also present an opportunity for future GBM treatment.
Topics: Animals; Humans; Mice; 11-beta-Hydroxysteroid Dehydrogenase Type 1; Brain Neoplasms; Carcinogenesis; Cevanes; Glioblastoma; Protein Isoforms; Ubiquitin-Protein Ligases
PubMed: 36980235
DOI: 10.3390/cells12060894 -
Frontiers in Genetics 2023is the main ingredient for Chinese folk medicine known as "Pimacao" due to its unique alkaloids. A diverse class of plant-specific metabolites having key...
is the main ingredient for Chinese folk medicine known as "Pimacao" due to its unique alkaloids. A diverse class of plant-specific metabolites having key pharmacological activities. There are limited studies on alkaloid synthesis and its metabolic pathways in plants. To elucidate the alkaloid pathway and identify novel biosynthetic enzymes and compounds in , transcriptome and metabolome profiling has been conducted in leaves and roots. The transcriptome of leaves and roots yielded 190,161 unigenes, of which 33,942 genes expressed differentially (DEGs) in both tissues. Three enriched regulatory pathways (isoquinoline alkaloid biosynthesis, indole alkaloid biosynthesis and tropane, piperidine and pyridine alkaloid biosynthesis) and a considerable number of genes such as , , , , , , were discovered in association with the biosynthesis of alkaloids in leaves and roots. Some transcription factor families, i.e., , , , , , , , , , , and were also found to have a prominent role in regulating the synthesis of alkaloids and steroidal alkaloids in the leaves and roots of . The metabolome analysis revealed 74 significantly accumulated metabolites, with 55 differentially accumulated in leaves compared to root tissues. Out of 74 metabolites, 18 alkaloids were highly accumulated in the roots. A novel alkaloid compound viz; 3-Vanilloylygadenine was discovered in root samples. Conjoint analysis of transcriptome and metabolome studies has also highlighted potential genes involved in regulation and transport of alkaloid compounds. Here, we have presented a comprehensive metabolic and transcriptome profiling of tissues. In earlier reports, only the roots were reported as a rich source of alkaloid biosynthesis, but the current findings revealed both leaves and roots as significant manufacturing factories for alkaloid biosynthesis.
PubMed: 36741317
DOI: 10.3389/fgene.2023.1023433 -
Clinical Toxicology (Philadelphia, Pa.) Dec 2022The genus is composed of plants containing a diverse set of steroidal alkaloids. plant material has been utilized for centuries as herbal medicines, however the...
INTRODUCTION
The genus is composed of plants containing a diverse set of steroidal alkaloids. plant material has been utilized for centuries as herbal medicines, however the alkaloids have such a low therapeutic index that they are not used in modern medicine. Here we report an incident of inadvertent ingestion of by hikers in Georgia that allowed detection, and in several instances identification of alkaloids from the plant, and correlated their presence within patient blood and breast milk specimens.
CASE HISTORY
Eight patients, three male and five female, presented in the spring of 2020 and 2021 with symptoms requiring emergent medical attention after ingestion of All patients believed the plants to be a local native species of wild leek, , locally known as ramps. Plants were identified using photographs as well as fresh and cooked plant material provided by patients, in consultation with botanists at the University of Georgia Herbarium. Written consent was obtained from all patients for collection of blood and breast milk specimens for laboratory identification of alkaloids.
METHODS
plant material, and patient serum and breast milk were analyzed by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF) to identify steroidal alkaloids.
RESULTS
The extract was confirmed to contain cyclopamine, veratramine, jervine, and muldamine. Two out of the eight patients had detectable concentrations of alkaloids. Of the alkaloids identified in the plant, cyclopamine and jervine were detected within patient serum, and cyclopamine and veratramine were observed to be present in breast milk.
DISCUSSION
Toxicity resulting from steroidal alkaloids has primarily been reported from and . This is the second report of poisoning. The present work reports for the first time the presence of muldamine and jervine within . This work provides the first instance of identification of alkaloids in breast milk. Thus, the findings presented herein add to literature record causative agents contributing to the toxicity of when ingested and potential for secondary poisoning through breastfeeding.
CONCLUSION
toxicity was observed to cause nausea, vomiting, hypotension, bradycardia, abdominal pain, light-headedness, blurred vision, and tingling in the arms. Patients experiencing mild symptoms improved with supportive care, IV fluids, and antiemetics, but hemodynamically unstable patients required atropine and vasopressors. This study demonstrated that more lipophilic alkaloids can be passed along in breast milk, which suggests additional precautions may be critical to limit further poisonings.
Topics: Female; Humans; Veratrum; Milk, Human; Veratrum Alkaloids; Alkaloids; Plant Poisoning
PubMed: 36301078
DOI: 10.1080/15563650.2022.2132166 -
International Journal of Molecular... Oct 2022The effects of lacosamide (LCS, Vimpat), an anti-convulsant and analgesic, on voltage-gated Na current () were investigated. LCS suppressed both the peak (transient, )...
The effects of lacosamide (LCS, Vimpat), an anti-convulsant and analgesic, on voltage-gated Na current () were investigated. LCS suppressed both the peak (transient, ) and sustained (late, ) components of with the IC values of 78 and 34 μM found in GH cells and of 112 and 26 μM in Neuro-2a cells, respectively. In GH3 cells, the voltage-dependent hysteresis of persistent () during the triangular ramp pulse was strikingly attenuated, and the decaying time constant (τ) of or during a train of depolarizing pulses was further shortened by LCS. The recovery time course from the block elicited by the preceding conditioning train can be fitted by two exponential processes, while the single exponential increase in current recovery without a conditioning train was adequately fitted. The fast and slow τ's of recovery from the block by the same conditioning protocol arose in the presence of LCS. In Neuro-2a cells, the strength of the instantaneous window () during the rapid ramp pulse was reduced by LCS. This reduction could be reversed by tefluthrin. Moreover, LCS accelerated the inactivation time course of activated by pulse train stimulation, and veratridine reversed its decrease in the decaying τ value in current inactivation. The docking results predicted the capability of LCS binding to some amino-acid residues in sodium channels owing to the occurrence of hydrophobic contact. Overall, our findings unveiled that LCS can interact with the sodium channels to alter the magnitude, gating, voltage-dependent hysteresis behavior, and use dependence of in excitable cells.
Topics: Ions; Lacosamide; Sodium; Sodium Channels; Veratridine
PubMed: 36233266
DOI: 10.3390/ijms231911966 -
Bioscience Reports Oct 2022Peimine, a bioactive substance isolated from Chinese medicine Fritillaria, can potentially suppress pulmonary fibrosis (PF); however, its therapeutic mechanism remains...
Peimine, a bioactive substance isolated from Chinese medicine Fritillaria, can potentially suppress pulmonary fibrosis (PF); however, its therapeutic mechanism remains unclear. Recent evidence suggests the participation of M2-type macrophages in the pathogenesis of PF. The present study aimed to investigate the effect of peimine on a bleomycin (BLM)-induced PF rat model and the underlying mechanism of this effect. After BLM administration, peimine was administered to rats from day 29 to day 42, with pirfenidone (PFD) as a positive control. H&E and Masson's trichrome stain were used to analyze histological changes. Q-PCR and western blotting were used to measure mRNA levels and protein levels, respectively. High-throughput RNA sequencing (RNA-seq) technology detected the differentially expressed genes (DEGs) regulated by peimine. Our results revealed that peimine treatment significantly ameliorated BLM-induced PF by suppressing histological changes and collagen deposition. In addition, peimine decreased the number of M2 macrophages and the expression of profibrotic factors. RNA-seq results showed that DEGs regulated by peimine in IL-4-induced macrophages were mainly associated with immune system processes, the PI3K/Akt pathway, and the MAPKs pathway. Then, immunofluorescence assay and western blot results demonstrated that peimine treatment suppressed the expression of p-p38 MAPK and p-Akt (s473) and also inhibited the nuclear translocation of p-STAT6. In conclusion, the present study demonstrated that peimine has a protective effect on PF through the suppression of M2 polarization of macrophages by inhibiting the STAT6, p38 MAPK, and Akt signals.
Topics: Animals; Bleomycin; Cevanes; Collagen; Interleukin-4; Macrophages; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pulmonary Fibrosis; RNA, Messenger; Rats; STAT6 Transcription Factor; p38 Mitogen-Activated Protein Kinases
PubMed: 36111628
DOI: 10.1042/BSR20220986 -
Molecules (Basel, Switzerland) Aug 2022Plants of the genus have been used throughout history for their emetic properties, rheumatism, and for the treatment of high blood pressure. However, inadvertent... (Review)
Review
Plants of the genus have been used throughout history for their emetic properties, rheumatism, and for the treatment of high blood pressure. However, inadvertent consumption of these plants, which resemble wild ramps, induces life-threatening side effects attributable to an abundance of steroidal alkaloids. Several of the steroidal alkaloids from spp. have been investigated for their ability to antagonize the Hedgehog (Hh) signaling pathway, a key pathway for embryonic development and cell proliferation. Uncontrolled activation of this pathway is linked to the development of various cancers; most notably, basal cell carcinoma and acute myeloid leukemia. Additional investigation of spp. may lead to the identification of novel alkaloids with the potential to serve as chemotherapeutics. is a relatively uncommon species of that resides in the southeastern regions of North America. The phytochemical profile of this plant remains largely unexplored; however, bioactive steroidal alkaloids, including cyclopamine, veratramine, veratridine, and verazine were identified in its extract. The structural elucidation and bioactivity assessment of steroidal alkaloids in lesser abundance within the extract of may yield potent Hh pathway inhibitors. This review seeks to consolidate the botanical and phytochemical information regarding
Topics: Alkaloids; Hedgehog Proteins; Phytochemicals; Plant Extracts; Steroids; Veratrum
PubMed: 36014585
DOI: 10.3390/molecules27165349