RESUMO
We tested a newly described molecular memory system, CCR5 signaling, for its role in recovery after stroke and traumatic brain injury (TBI). CCR5 is uniquely expressed in cortical neurons after stroke. Post-stroke neuronal knockdown of CCR5 in pre-motor cortex leads to early recovery of motor control. Recovery is associated with preservation of dendritic spines, new patterns of cortical projections to contralateral pre-motor cortex, and upregulation of CREB and DLK signaling. Administration of a clinically utilized FDA-approved CCR5 antagonist, devised for HIV treatment, produces similar effects on motor recovery post stroke and cognitive decline post TBI. Finally, in a large clinical cohort of stroke patients, carriers for a naturally occurring loss-of-function mutation in CCR5 (CCR5-Δ32) exhibited greater recovery of neurological impairments and cognitive function. In summary, CCR5 is a translational target for neural repair in stroke and TBI and the first reported gene associated with enhanced recovery in human stroke.
Assuntos
Lesões Encefálicas Traumáticas/terapia , Receptores CCR5/metabolismo , Acidente Vascular Cerebral/terapia , Idoso , Idoso de 80 Anos ou mais , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Espinhas Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Córtex Motor/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios/metabolismo , Receptores CCR5/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodosRESUMO
Following peripheral nerve injury, denervated tissues can be reinnervated via regeneration of injured neurons or collateral sprouting of neighboring uninjured afferents into denervated territory. While there has been substantial focus on mechanisms underlying regeneration, collateral sprouting has received less attention. Here, we used immunohistochemistry and genetic neuronal labeling to define the subtype specificity of sprouting-mediated reinnervation of plantar hindpaw skin in the mouse spared nerve injury (SNI) model, in which productive regeneration cannot occur. Following initial loss of cutaneous afferents in the tibial nerve territory, we observed progressive centripetal reinnervation by multiple subtypes of neighboring uninjured fibers into denervated glabrous and hairy plantar skin of male mice. In addition to dermal reinnervation, CGRP-expressing peptidergic fibers slowly but continuously repopulated denervated epidermis, Interestingly, GFRα2-expressing nonpeptidergic fibers exhibited a transient burst of epidermal reinnervation, followed by a trend towards regression. Presumptive sympathetic nerve fibers also sprouted into denervated territory, as did a population of myelinated TrkC lineage fibers, though the latter did so inefficiently. Conversely, rapidly adapting Aß fiber and C fiber low threshold mechanoreceptor (LTMR) subtypes failed to exhibit convincing sprouting up to 8 weeks after nerve injury in males or females. Optogenetics and behavioral assays in male mice further demonstrated the functionality of collaterally sprouted fibers in hairy plantar skin with restoration of punctate mechanosensation without hypersensitivity. Our findings advance understanding of differential collateral sprouting among sensory neuron subpopulations and may guide strategies to promote the progression of sensory recovery or limit maladaptive sensory phenomena after peripheral nerve injury.
Assuntos
Traumatismos dos Nervos Periféricos , Feminino , Camundongos , Masculino , Animais , Regeneração Nervosa/fisiologia , Pele/inervação , Neurogênese , Neurônios Aferentes/fisiologiaRESUMO
Toll-like receptors (TLRs) play an important role in the innate immune response after CNS injury. Although TLR4 is one of the best characterized, its role in chronic stages after spinal cord injury (SCI) is not well understood. We examined the role of TLR4 signaling in injury-induced responses at 1â d, 7â d, and 8â weeks after spinal cord contusion injury in adult female TLR4 null and wild-type mice. Analyses include secondary damage, a range of transcriptome and protein analyses of inflammatory, cell death, and extracellular matrix (ECM) molecules, as well as immune cell infiltration and changes in axonal sprouting and locomotor recovery. Lack of TLR4 signaling results in reduced neuronal and myelin loss, reduced activation of NFκB, and decreased expression of inflammatory cytokines and necroptotic cell death pathway at a late time point (8â weeks) after injury. TLR4 null mice also showed reduction of scar-related ECM molecules at 8â weeks after SCI, accompanied by increase in ECM molecules associated with perineuronal nets, increased sprouting of serotonergic fibers, and improved locomotor recovery. These findings reveal novel effects of TLR4 signaling in chronic SCI. We show that TLR4 influences inflammation, cell death, and ECM deposition at late-stage post-injury when secondary injury processes are normally considered to be over. This highlights the potential for late-stage targeting of TLR4 as a potential therapy for chronic SCI.
Assuntos
Citocinas , Traumatismos da Medula Espinal , Camundongos , Feminino , Animais , Citocinas/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Neurônios/metabolismo , Inflamação/metabolismo , Camundongos Knockout , Medula Espinal/metabolismo , Recuperação de Função Fisiológica/fisiologiaRESUMO
Pre-harvest sprouting (PHS) is a significant threat to global food security due to its association with losses in both yield and quality. Among the genes involved in PHS resistance in wheat, PHS-3D (TaMyb10-D) plays a crucial role. Here, we characterized the sequence variations of TaMyb10 genes in 416 bread wheat and 302 Aegilops tauschii accessions. Within TaMyb10-A sequences, we identified a deletion ranging from 214 to 305 bp in the signal and amino acid coding region, present in 61.3% of the accessions. Similarly, 79.3% of the TaMyb10-B sequences within the third exon region exhibited a 19 bp deletion. Additionally, 40.8% of the accessions lacked the 2.4 Mb fragment (in/del mutations) on Chr3D, where TaMyb10-D/PHS-3D was located. Interestingly, the geographical distribution of accessions showed little correlation with the divergence of TaMyb10. TaMyb10-A-IIIDele, TaMyb10-B-IVDele, and TaMyb10-D-VDele genotypes were prevalent in wheat populations across continents. Despite their structural variations, the five distinct protein types exhibited comparable ability to bind the promoters of downstream genes in the flavonoid and ABA pathways, such as CHS, DFR, and NCED. Furthermore, the combination of TaMyb10 homologs was significantly associated with grain color and germination percentages. Accessions exclusively harboring TaMyb10-D displayed red seed color and reduced germination percentages, indicating the predominant role of TaMyb10-D compared to TaMyb10-A and TaMyb10-B. This comprehensive investigation enhances our understanding of the structural variations and functional divergence of TaMyb10, providing valuable insights and resources for improving PHS resistance in wheat.
Assuntos
Proteínas de Plantas , Triticum , Triticum/genética , Triticum/fisiologia , Triticum/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Aegilops/genética , Germinação/genética , Variação Genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologiaRESUMO
The aleurone layer in cereal grains acts as a major reservoir of essential mineral nutrients, significantly influencing seed germination. However, the molecular mechanism underlying the redistribution of nutrients from the aleurone layer in the germinating seed is still not well understood. Here, in rice, we identified a plasma membrane (PM) localized magnesium transporter, MAGNESIUM RELEASE TRANSPORTER 3 (MGR3), is critical for seed germination. OsMGR3 is predominantly expressed in the aleurone layer cells of endosperm, facilitating magnesium remobilization during germination. Non-invasive Micro-test Technology assay data demonstrated that the loss-of-function of OsMGR3 restrained magnesium efflux from the aleurone layer. In the embryo/endosperm grafting experiment, we observed that the mutation of OsMGR3 in the aleurone layer suppressed the growth and differentiation of the embryo during germination. Furthermore, magnesium fluorescence imaging revealed the osmgr3 mutant seeds showed impaired exportation of aleurone layer-stored magnesium to the embryo, consequently delaying germination. Importantly, we discovered that disrupting OsMGR3 could inhibit pre-harvest sprouting without affecting rice yield and quality. Therefore, the magnesium efflux transporter OsMGR3 in the aleurone layer represents a promising genetic target for future agronomic trait improvement.
Assuntos
Membrana Celular , Germinação , Magnésio , Oryza , Proteínas de Plantas , Sementes , Oryza/genética , Oryza/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Magnésio/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Sementes/genética , Sementes/metabolismo , Sementes/crescimento & desenvolvimento , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Endosperma/metabolismo , Endosperma/genética , MutaçãoRESUMO
Degeneration of dopaminergic neurons in the substantia nigra and their striatal axon terminals causes cardinal motor symptoms of Parkinson's disease. In idiopathic cases, high levels of mitochondrial DNA alterations, leading to mitochondrial dysfunction, are a central feature of these vulnerable neurons. Here we present a mouse model expressing the K320E variant of the mitochondrial helicase Twinkle in dopaminergic neurons, leading to accelerated mitochondrial DNA mutations. These K320E-TwinkleDaN mice showed normal motor function at 20 months of age, although â¼70% of nigral dopaminergic neurons had perished. Remaining neurons still preserved â¼75% of axon terminals in the dorsal striatum and enabled normal dopamine release. Transcriptome analysis and viral tracing confirmed compensatory axonal sprouting of the surviving neurons. We conclude that a small population of substantia nigra dopaminergic neurons is able to adapt to the accumulation of mitochondrial DNA mutations and maintain motor control.
Assuntos
Corpo Estriado , Neurônios Dopaminérgicos , Substância Negra , Animais , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/metabolismo , Substância Negra/patologia , Substância Negra/metabolismo , Camundongos , Corpo Estriado/patologia , Corpo Estriado/metabolismo , Camundongos Transgênicos , DNA Mitocondrial/genética , Atividade Motora/fisiologia , Mutação , DNA Helicases/genética , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Masculino , Dopamina/metabolismoRESUMO
Lymphatic vessels are important for tissue fluid homeostasis, lipid absorption, and immune cell trafficking and are involved in the pathogenesis of several human diseases. The mechanisms by which the lymphatic vasculature network is formed, remodeled, and adapted to physiological and pathological challenges are controlled by an intricate balance of growth factor and biomechanical cues. These transduce signals for the readjustment of gene expression and lymphatic endothelial migration, proliferation, and differentiation. In this review, we describe several of these cues and how they are integrated for the generation of functional lymphatic vessel networks.
Assuntos
Linfangiogênese , Animais , Membrana Basal/fisiologia , Carcinogênese , Inflamação/fisiopatologia , Integrinas/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Vasos Linfáticos/embriologia , Camundongos , Comunicação Parácrina , Fator C de Crescimento do Endotélio Vascular/fisiologia , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with cell cycle, immune response and neuronal signaling. The MM transcriptional signature was consistent with metastatic MM infiltration to the DRG, a never-before described feature of the disease that we further demonstrated histologically. In the DRG, MM cells caused loss of vascularization and neuronal injury, which may contribute to late-stage MIBP. Interestingly, the transcriptional signature of a MM patient was consistent with MM cell infiltration to the DRG. Overall, our results suggest that MM induces a plethora of peripheral nervous system alterations that may contribute to the failure of current analgesics and suggest neuroprotective drugs as appropriate strategies to treat early onset MIBP.SIGNIFICANCE STATEMENT Multiple myeloma (MM) is a painful bone marrow cancer that significantly impairs the quality of life of the patients. Analgesic therapies for myeloma-induced bone pain (MIBP) are limited and often ineffective, and the mechanisms of MIBP remain unknown. In this manuscript, we describe cancer-induced periosteal nerve sprouting in a mouse model of MIBP, where we also encounter metastasis to the dorsal root ganglia (DRG), a never-before described feature of the disease. Concomitant to myeloma infiltration, the lumbar DRGs presented blood vessel damage and transcriptional alterations, which may mediate MIBP. Explorative studies on human tissue support our preclinical findings. Understanding the mechanisms of MIBP is crucial to develop targeted analgesic with better efficacy and fewer side effects for this patient population.
Assuntos
Doenças Ósseas , Mieloma Múltiplo , Tecido Nervoso , Humanos , Camundongos , Masculino , Animais , Mieloma Múltiplo/complicações , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Qualidade de Vida , Dor/metabolismo , Tecido Nervoso/metabolismo , Tecido Nervoso/patologia , Gânglios Espinais/metabolismoRESUMO
The peripheral nervous system is a key regulator of cancer progression. In pancreatic ductal adenocarcinoma (PDAC), the sympathetic branch of the autonomic nervous system inhibits cancer development. This inhibition is associated with extensive sympathetic nerve sprouting in early pancreatic cancer precursor lesions. However, the underlying mechanisms behind this process remain unclear. This study aimed to investigate the roles of pancreatic Schwann cells in the structural plasticity of sympathetic neurons. We examined the changes in the number and distribution of Schwann cells in a transgenic mouse model of PDAC and in a model of metaplastic pancreatic lesions induced by chronic inflammation. Schwann cells proliferated and expanded simultaneously with new sympathetic nerve sprouts in metaplastic/neoplastic pancreatic lesions. Sparse genetic labeling showed that individual Schwann cells in these lesions had a more elongated and branched structure than those under physiological conditions. Schwann cells overexpressed neurotrophic factors, including glial cell-derived neurotrophic factor (GDNF). Sympathetic neurons upregulated the GDNF receptors and exhibited enhanced neurite growth in response to GDNF in vitro. Selective genetic deletion of Gdnf in Schwann cells completely blocked sympathetic nerve sprouting in metaplastic pancreatic lesions in vivo. This study demonstrated that pancreatic Schwann cells underwent adaptive reprogramming during early cancer development, supporting a protective antitumor neuronal response. These finding could help to develop new strategies to modulate cancer associated neural plasticity.
Assuntos
Camundongos Transgênicos , Neoplasias Pancreáticas , Células de Schwann , Animais , Células de Schwann/metabolismo , Células de Schwann/patologia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Camundongos , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/genética , Reprogramação Celular/fisiologia , Pâncreas/patologia , Pâncreas/inervação , Pâncreas/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios/metabolismo , Neurônios/patologia , Camundongos Endogâmicos C57BLRESUMO
Previous studies have shown that Vasohibin 1 (Vash1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo Recently, Vash1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here, we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash1 knockdown. Vash1 depletion in zebrafish specifically affected secondary sprouting from the posterior cardinal vein, increasing endothelial cell divisions and cell number in the sprouts. We show that altering secondary sprout numbers and structure upon Vash1 depletion leads to defective lymphatic vessel formation and ectopic lymphatic progenitor specification in the zebrafish trunk.
Assuntos
Proteínas de Ciclo Celular/genética , Desenvolvimento Embrionário/genética , Linfangiogênese/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Sequência Conservada , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Microtúbulos/metabolismo , Modelos BiológicosRESUMO
Blood vessel growth and remodelling are essential during embryonic development and disease pathogenesis. The diversity of endothelial cells (ECs) is transcriptionally evident and ECs undergo dynamic changes in gene expression during vessel growth and remodelling. Here, we investigated the role of the histone acetyltransferase HBO1 (KAT7), which is important for activating genes during development and for histone H3 lysine 14 acetylation (H3K14ac). Loss of HBO1 and H3K14ac impaired developmental sprouting angiogenesis and reduced pathological EC overgrowth in the retinal endothelium. Single-cell RNA sequencing of retinal ECs revealed an increased abundance of tip cells in Hbo1-deficient retinas, which led to EC overcrowding in the retinal sprouting front and prevented efficient tip cell migration. We found that H3K14ac was highly abundant in the endothelial genome in both intra- and intergenic regions, suggesting that HBO1 acts as a genome organiser that promotes efficient tip cell behaviour necessary for sprouting angiogenesis. This article has an associated 'The people behind the papers' interview.
Assuntos
Histona Acetiltransferases/metabolismo , Neovascularização Patológica/metabolismo , Acetilação , Animais , Movimento Celular/fisiologia , Células Cultivadas , Desenvolvimento Embrionário/fisiologia , Células Endoteliais/metabolismo , Feminino , Histonas/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Lisina/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: B-box (BBX) proteins are a type of zinc finger proteins containing one or two B-box domains. They play important roles in development and diverse stress responses of plants, yet their roles in wheat remain unclear. RESULTS: In this study, 96 BBX genes were identified in the wheat genome and classified into five subfamilies. Subcellular localization prediction results showed that 68 TaBBXs were localized in the nucleus. Protein interaction prediction analysis indicated that interaction was one way that these proteins exerted their functions. Promoter analysis indicated that TaBBXs may play important roles in light signal, hormone, and stress responses. qRT-PCR analysis revealed that 14 TaBBXs were highly expressed in seeds compared with other tissues. These were probably involved in seed dormancy and germination, and their expression patterns were investigated during dormancy acquisition and release in the seeds of wheat varieties Jing 411 and Hongmangchun 21, showing significant differences in seed dormancy and germination phenotypes. Subcellular localization analysis confirmed that the three candidates TaBBX2-2 A, TaBBX4-2 A, and TaBBX11-2D were nuclear proteins. Transcriptional self-activation experiments further demonstrated that TaBBX4-2A was transcriptionally active, but TaBBX2-2A and TaBBX11-2D were not. Protein interaction analysis revealed that TaBBX2-2A, TaBBX4-2A, and TaBBX11-2D had no interaction with each other, while TaBBX2-2A and TaBBX11-2D interacted with each other, indicating that TaBBX4-2A may regulate seed dormancy and germination by transcriptional regulation, and TaBBX2-2A and TaBBX11-2D may regulate seed dormancy and germination by forming a homologous complex. CONCLUSIONS: In this study, the wheat BBX gene family was identified and characterized at the genomic level by bioinformatics analysis. These observations provide a theoretical basis for future studies on the functions of BBXs in wheat and other species.
Assuntos
Germinação , Família Multigênica , Dormência de Plantas , Proteínas de Plantas , Triticum , Triticum/genética , Triticum/fisiologia , Dormência de Plantas/genética , Germinação/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Simulação por Computador , FilogeniaRESUMO
BACKGROUND: Class III peroxidases (PODs) perform crucial functions in various developmental processes and responses to biotic and abiotic stresses. However, their roles in wheat seed dormancy (SD) and germination remain elusive. RESULTS: Here, we identified a wheat class III POD gene, named TaPer12-3A, based on transcriptome data and expression analysis. TaPer12-3A showed decreasing and increasing expression trends with SD acquisition and release, respectively. It was highly expressed in wheat seeds and localized in the endoplasmic reticulum and cytoplasm. Germination tests were performed using the transgenic Arabidopsis and rice lines as well as wheat mutant mutagenized with ethyl methane sulfonate (EMS) in Jing 411 (J411) background. These results indicated that TaPer12-3A negatively regulated SD and positively mediated germination. Further studies showed that TaPer12-3A maintained H2O2 homeostasis by scavenging excess H2O2 and participated in the biosynthesis and catabolism pathways of gibberellic acid and abscisic acid to regulate SD and germination. CONCLUSION: These findings not only provide new insights for future functional analysis of TaPer12-3A in regulating wheat SD and germination but also provide a target gene for breeding wheat varieties with high pre-harvest sprouting resistance by gene editing technology.
Assuntos
Germinação , Dormência de Plantas , Triticum , Triticum/genética , Triticum/enzimologia , Triticum/fisiologia , Dormência de Plantas/genética , Germinação/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Peróxido de Hidrogênio/metabolismo , Giberelinas/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Peroxidases/genética , Peroxidases/metabolismo , Plantas Geneticamente Modificadas , Ácido Abscísico/metabolismo , Genes de PlantasRESUMO
Rapeseed (Brassica napus L.) with short or no dormancy period are easy to germinate before harvest (pre-harvest sprouting, PHS). PHS has seriously decreased seed weight and oil content in B. napus. Short-chain dehydrogenase/ reductase (SDR) genes have been found to related to seed dormancy by promoting ABA biosynthesis in rice and Arabidopsis. In order to clarify whether SDR genes are the key factor of seed dormancy in B. napus, homology sequence blast, protein physicochemical properties, conserved motif, gene structure, cis-acting element, gene expression and variation analysis were conducted in present study. Results shown that 142 BnaSDR genes, unevenly distributed on 19 chromosomes, have been identified in B. napus genome. Among them, four BnaSDR gene clusters present in chromosome A04ãA05ãC03ãC04 were also identified. These 142 BnaSDR genes were divided into four subfamilies on phylogenetic tree. Members of the same subgroup have similar protein characters, conserved motifs, gene structure, cis-acting elements and tissue expression profiles. Specially, the expression levels of genes in subgroup A, B and C were gradually decreased, but increased in subgroup D with the development of seeds. Among seven higher expressed genes in group D, six BnaSDR genes were significantly higher expressed in weak dormancy line than that in nondormancy line. And the significant effects of BnaC01T0313900ZS and BnaC03T0300500ZS variation on seed dormancy were also demonstrated in present study. These findings provide a key information for investigating the function of BnaSDRs on seed dormancy in B. napus.
Assuntos
Brassica napus , Brassica rapa , Brassica napus/genética , Brassica napus/metabolismo , Dormência de Plantas/genética , Perfilação da Expressão Gênica , Filogenia , Brassica rapa/genética , Sementes/genética , Sementes/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
BACKGROUND: Vascular growth followed by vessel specification is crucial for the establishment of a hierarchical blood vascular network. We have shown that TIE2 is required for vein development while little is known about its homologue TIE1 (tyrosine kinase with immunoglobulin-like and EGF [epithelial growth factor]-like domains 1) in this process. METHODS: We analyzed functions of TIE1 as well as its synergy with TIE2 in the regulation of vein formation by employing genetic mouse models targeting Tie1, Tek, and Nr2f2, together with in vitro cultured endothelial cells to decipher the underlying mechanism. RESULTS: Cardinal vein growth appeared normal in TIE1-deficient mice, whereas TIE2 deficiency altered the identity of cardinal vein endothelial cells with the aberrant expression of DLL4 (delta-like canonical Notch ligand 4). Interestingly, the growth of cutaneous veins, which was initiated at approximately embryonic day 13.5, was retarded in mice lack of TIE1. TIE1 deficiency disrupted the venous integrity, displaying increased sprouting angiogenesis and vascular bleeding. Abnormal venous sprouts with defective arteriovenous alignment were also observed in the mesenteries of Tie1-deleted mice. Mechanistically, TIE1 deficiency resulted in the decreased expression of venous regulators including TIE2 and COUP-TFII (chicken ovalbumin upstream promoter transcription factor, encoded by Nr2f2, nuclear receptor subfamily 2 group F member 2) while angiogenic regulators were upregulated. The alteration of TIE2 level by TIE1 insufficiency was further confirmed by the siRNA-mediated knockdown of Tie1 in cultured endothelial cells. Interestingly, TIE2 insufficiency also reduced the expression of TIE1. Combining the endothelial deletion of Tie1 with 1 null allele of Tek resulted in a progressive increase of vein-associated angiogenesis leading to the formation of vascular tufts in retinas, whereas the loss of Tie1 alone produced a relatively mild venous defect. Furthermore, the induced deletion of endothelial Nr2f2 decreased both TIE1 and TIE2. CONCLUSIONS: Findings from this study imply that TIE1 and TIE2, together with COUP-TFII, act in a synergistic manner to restrict sprouting angiogenesis during the development of venous system.
Assuntos
Receptor de TIE-1 , Receptor TIE-2 , Camundongos , Animais , Receptor de TIE-1/genética , Receptor de TIE-1/metabolismo , Receptor TIE-2/genética , Receptor TIE-2/metabolismo , Células Endoteliais/metabolismo , Transdução de Sinais , VeiasRESUMO
BACKGROUND: Nanotechnology holds revolutionary potential in the field of agriculture, with zinc oxide nanoparticles (ZnO NPs) demonstrating advantages in promoting crop growth. Enhanced photosynthetic efficiency is closely linked to improved vigor and superior quality in tea plants, complemented by the beneficial role of phyllosphere microorganisms in maintaining plant health. However, the effects of ZnO NPs on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms have not been fully investigated. RESULTS: This study investigated the photosynthetic physiological parameters of tea plants under the influence of ZnO NPs, the content of key photosynthetic enzymes such as RubisCO, chlorophyll content, chlorophyll fluorescence parameters, transcriptomic and extensive targeted metabolomic profiles of leaves and new shoots, mineral element composition in these tissues, and the epiphytic and endophytic microbial communities within the phyllosphere. The results indicated that ZnO NPs could enhance the photosynthesis of tea plants, upregulate the expression of some genes related to photosynthesis, increase the accumulation of photosynthetic products, promote the development of new shoots, and alter the content of various mineral elements in the leaves and new shoots of tea plants. Furthermore, the application of ZnO NPs was observed to favorably influence the microbial community structure within the phyllosphere of tea plants. This shift in microbial community dynamics suggests a potential for ZnO NPs to contribute to plant health and productivity by modulating the phyllosphere microbiome. CONCLUSION: This study demonstrates that ZnO NPs have a positive impact on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms, which can improve the growth condition of tea plants. These findings provide new scientific evidence for the application of ZnO NPs in sustainable agricultural development and contribute to advancing research in nanobiotechnology aimed at enhancing crop yield and quality.
Assuntos
Camellia sinensis , Nanopartículas Metálicas , Microbiota , Fotossíntese , Folhas de Planta , Brotos de Planta , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Fotossíntese/efeitos dos fármacos , Camellia sinensis/microbiologia , Brotos de Planta/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Folhas de Planta/microbiologia , Nanopartículas Metálicas/química , Clorofila/metabolismo , Nanopartículas/químicaRESUMO
Ozark chinquapin (Castanea ozarkensis Ashe) is a forest tree, endemic to the Ozark Mountain region in Eastern United States. Its nutritious nuts were consumed by Native Americans, European settlers, livestock, and wild animals and its wood was an important rot-resistant construction material. Once a significant tree in regional forest communities, the species was nearly eradicated by a chestnut blight caused by Cryphonectria parasitca (Murill) Barr fungus. Some individuals have survived as sprouts from adventitious root buds, but they rarely reach reproductive maturity. While some in situ restoration efforts are underway, the development of a viable ex situ germplasm preservation method is critical to the conservation of this important food-bearing species. Our experiment aimed to develop a cryopreservation method for C. ozarkensis dormant winter buds subjected to eight experimental treatments before desiccation, slow cooling, and storage in liquid nitrogen vapor. The highest post cryogenic viability was 91.2 % for dormant buds pretreated with 0.3 M sucrose for 16 h followed by 0.75 M sucrose for 3 h; this treatment is suggested for cryopreservation of dormant winter buds of Ozark chinquapin germplasm.
Assuntos
Temperatura Baixa , Criopreservação , Humanos , Criopreservação/métodos , Brotos de Planta , Transição de Fase , Árvores , SacaroseRESUMO
Angiogenesis, the fundamental process by which new blood vessels form from existing ones, depends on precise spatial and temporal gene expression within specific compartments of the endothelium. However, the molecular links between proangiogenic signals and downstream gene expression remain unclear. During sprouting angiogenesis, the specification of endothelial cells into the tip cells that lead new blood vessel sprouts is coordinated by vascular endothelial growth factor A (VEGFA) and Delta-like ligand 4 (Dll4)/Notch signaling and requires high levels of Notch ligand DLL4. Here, we identify MEF2 transcription factors as crucial regulators of sprouting angiogenesis directly downstream from VEGFA. Through the characterization of a Dll4 enhancer directing expression to endothelial cells at the angiogenic front, we found that MEF2 factors directly transcriptionally activate the expression of Dll4 and many other key genes up-regulated during sprouting angiogenesis in both physiological and tumor vascularization. Unlike ETS-mediated regulation, MEF2-binding motifs are not ubiquitous to all endothelial gene enhancers and promoters but are instead overrepresented around genes associated with sprouting angiogenesis. MEF2 target gene activation is directly linked to VEGFA-induced release of repressive histone deacetylases and concurrent recruitment of the histone acetyltransferase EP300 to MEF2 target gene regulatory elements, thus establishing MEF2 factors as the transcriptional effectors of VEGFA signaling during angiogenesis.
Assuntos
Células Endoteliais/citologia , Células Endoteliais/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição MEF2/metabolismo , Neovascularização Fisiológica/genética , Animais , Células Cultivadas , Embrião não Mamífero , Células Endoteliais/enzimologia , Elementos Facilitadores Genéticos/genética , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fatores de Transcrição MEF2/química , Fatores de Transcrição MEF2/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Neovascularização Patológica/genética , Domínios e Motivos de Interação entre Proteínas , Retina/embriologia , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Peixe-ZebraRESUMO
The post-harvest phase of potato tuber dormancy and sprouting are essential in determining the economic value. The intricate transition from dormancy to active growth is influenced by multiple factors, including environmental factors, carbohydrate metabolism, and hormonal regulation. Well-established environmental factors such as temperature, humidity, and light play pivotal roles in these processes. However, recent research has expanded our understanding to encompass other novel influences such as magnetic fields, cold plasma treatment, and UV-C irradiation. Hormones like abscisic acid (ABA), gibberellic acid (GA), cytokinins (CK), auxin, and ethylene (ETH) act as crucial messengers, while brassinosteroids (BRs) have emerged as key modulators of potato tuber sprouting. In addition, jasmonates (JAs), strigolactones (SLs), and salicylic acid (SA) also regulate potato dormancy and sprouting. This review article delves into the intricate study of potato dormancy and sprouting, emphasizing the impact of environmental conditions, carbohydrate metabolism, and hormonal regulation. It explores how various environmental factors affect dormancy and sprouting processes. Additionally, it highlights the role of carbohydrates in potato tuber sprouting and the intricate hormonal interplay, particularly the role of BRs. This review underscores the complexity of these interactions and their importance in optimizing potato dormancy and sprouting for agricultural practices.
Assuntos
Dormência de Plantas , Reguladores de Crescimento de Plantas , Tubérculos , Solanum tuberosum , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/metabolismo , Solanum tuberosum/fisiologia , Solanum tuberosum/genética , Tubérculos/crescimento & desenvolvimento , Tubérculos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Metabolismo dos CarboidratosRESUMO
Angiogenesis, or the development of blood vessels by growing from already-formed vessels, is observed in embryonic development, physiological cyclical processes such as wound healing, the encapsulation of foreign bodies, tumor growth, and some other situations. In this review, we analyze the cellular mechanisms of angiogenesis, namely, angiogenesis by sprouting, ansiform (by loop formation) angiogenesis, coalescent angiogenesis, and angiogenesis by intussusception (splitting the capillary into two channels). The analysis of data revealed a lot of unanswered questions and contradictions. Here, we propose several new models of angiogenesis explaining these contradictions.