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1.
Bioact Mater ; 40: 378-395, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38978801

RESUMO

Extracellular vesicles from skin-derived precursor Schwann cells (SKP-SC-EVs) promote neurite outgrowth in culture and enhance peripheral nerve regeneration in rats. This study aimed at expanding the application of SKP-SC-EVs in nerve grafting by creating a chitosan/PLGA-based, SKP-SC-EVs-containing tissue engineered nerve graft (TENG) to bridge a 40-mm long sciatic nerve defect in dogs. SKP-SC-EVs contained in TENGs significantly accelerated the recovery of hind limb motor and electrophysiological functions, supported the outgrowth and myelination of regenerated axons, and alleviated the denervation-induced atrophy of target muscles in dogs. To clarify the underlying molecular mechanism, we observed that SKP-SC-EVs were rich in a variety of miRNAs linked to the axon growth of neurons, and miR-30b-5p was the most important among others. We further noted that miR-30b-5p contained within SKP-SC-EVs exerted nerve regeneration-promoting effects by targeting the Sin3a/HDAC complex and activating the phosphorylation of ERK, STAT3 or CREB. Our findings suggested that SKP-SC-EVs-incorporating TENGs represent a novel type of bioactive material with potential application for peripheral nerve repair in the clinic.

2.
Forensic Sci Int ; 360: 112074, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823217

RESUMO

Synthetic cathinones, which are novel psychoactive substances, have caused major social problems worldwide. A substance called 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MMMP), which is employed as a commercial industrial photoinitiator for triggering polymerization, has a basic cathinone backbone; however, few reports regarding MMMP have been published. In the current study, three potential metabolites of MMMP-namely hydroxy-MMMP (HO-MMMP), HO-MMMP-sulfoxide (HO-MMMP-SO), and HO-MMMP-sulfone (HO-MMMP-SO2)-were successfully synthesized, and MMMP and these three potential metabolites were used as standards to establish an analytic method based on liquid chromatography-tandem mass spectrometry for the quantitative analysis of urine. This analytic method and related parameters-including dynamic range, limit of quantification, selectivity, precision, accuracy, carryover effect, matrix effect, interference, and dilution integrity-were optimized and validated. Forty urine samples from 1,691 individuals who abused drugs were determined to contain MMMP, HO-MMMP, HO-MMMP-SO, or HO-MMMP-SO2; the results of this study indicate that approximately 2.37 % of drug abusers in Taiwan consumed MMMP in 2023. These 40 urine samples were analyzed to investigate the metabolism of MMMP in humans. The results indicate that HO-MMMP-SO is the main metabolite in human urine. This study recommends HO-MMMP-SO with a concentration of 2 ng/mL as a target and cutoff value, respectively, for identifying individuals who have consumed MMMP.


Assuntos
Psicotrópicos , Espectrometria de Massas em Tandem , Humanos , Psicotrópicos/urina , Psicotrópicos/análise , Cromatografia Líquida , Propiofenonas/urina , Detecção do Abuso de Substâncias/métodos , Drogas Ilícitas/análise , Morfolinas/urina , Morfolinas/análise , Limite de Detecção
3.
ACS Nano ; 18(14): 10259-10269, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38551447

RESUMO

Water-induced electricity harvesting has gained much significance for energy sustainability. Bio-based hydrovoltaic materials increase the attractiveness of this strategy. Although promising, it faces a challenge due to its reliance on fresh water and its inherently low power output. Herein, the energy from alkalinity-gradient power generation demonstrated the feasibility of reuse of alkaline wastewater to develop an all-wood-based water-induced electric generator (WEG) based on ion concentration gradients. The intermittent water droplets bring about uneven distribution of electrolyte and endow delignified wood with the difference of ion concentration along aligned cellulose nanochannels, thus supplying electrical power. The practice of using alkali reservoirs, including industrial wastewater, further contributes to electricity generation. The cubic WEG with a side length of 2 cm can produce an ultrahigh open-circuit voltage of about 1.1 V and a short-circuit current of up to 320 µA. A power output of 6.75 µW cm-2 is correspondingly realized. Series-connected WEGs can be used as an energy source for commercial electronics and self-powered systems. Our design provides a double value proposition, allowing for sustainable energy generation and wastewater reuse.

4.
Exp Neurol ; 376: 114750, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38492636

RESUMO

Nerve injury often leads to severe dysfunction because of the lack of axon regeneration in adult mammal. Intriguingly a series of extracellular vesicles (EVs) have the obvious ability to accelerate the nerve repair. However, the detailed molecular mechanisms to describe that EVs switch neuron from a transmitter to a regenerative state have not been elucidated. This study elucidated the microRNA (miRNA) expression profiles of two types of EVs that promote nerve regeneration. The functions of these miRNAs were screened in vitro. Among the 12 overlapping miRNAs, miR-25-3p was selected for further analysis as it markedly promoted axon regeneration both in vivo and in vitro. Furthermore, knockdown experiments confirmed that PTEN and Klf4, which are the major inhibitors of axon regeneration, were the direct targets of miR-25-3p in dorsal root ganglion (DRG) neurons. The utilization of luciferase reporter assays and functional tests provided evidence that miR-25-3p enhances axon regeneration by targeting Tgif1. Additionally, miR-25-3p upregulated the phosphorylation of Erk. Furthermore, Rapamycin modulated the expression of miR-25-3p in DRG neurons. Finally, the pro-axon regeneration effects of EVs were confirmed by overexpressing miR-25-3p and Tgif1 knockdown in the optic nerve crush model. Thus, the enrichment of miR-25-3p in EVs suggests that it regulates axon regeneration, proving a potential cell-free treatment strategy for nerve injury.


Assuntos
Axônios , Vesículas Extracelulares , Gânglios Espinais , Proteínas de Homeodomínio , MicroRNAs , Regeneração Nervosa , Células de Schwann , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Regeneração Nervosa/fisiologia , Regeneração Nervosa/genética , Vesículas Extracelulares/metabolismo , Axônios/fisiologia , Células de Schwann/metabolismo , Gânglios Espinais/metabolismo , Gânglios Espinais/citologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Camundongos , Pele/metabolismo , Fator 4 Semelhante a Kruppel , Camundongos Endogâmicos C57BL , Células-Tronco/metabolismo
5.
Mol Divers ; 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504075

RESUMO

Halociline, a derivative of alkaloids, was isolated from the marine fungus Penicillium griseofulvum by our group. This remarkable compound exhibits promising antineoplastic activity, yet the precise molecular mechanisms underlying its anticancer properties remain enigmatic. To unravel these mechanisms, we employed an integrated approach of network pharmacology analysis, molecular docking simulations, and molecular dynamics simulations to explore halociline therapeutic targets for gastric cancer. The data from network pharmacology indicate that halociline targets MAPK1, MMP-9, and PIK3CA in gastric cancer cells, potentially mediated by diverse pathways including cancer, lipid metabolism, atherosclerosis, and EGFR tyrosine kinase inhibitor resistance. Notably, molecular docking and dynamics simulations revealed a high affinity between halociline and these targets, with free binding energies (ΔEtotal) of - 20.28, - 27.94, and - 25.97 kcal/mol for MAPK1, MMP-9, and PIK3CA, respectively. This study offers valuable insights into the potential molecular mechanism of halociline's inhibition of gastric cancer cells and serves as a valuable reference for future basic research efforts.

6.
Environ Toxicol ; 39(6): 3734-3745, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38546343

RESUMO

The development of resistance to Docetaxel (DTX) compromises its therapeutic efficacy and worsens the prognosis of prostate cancer (PCa), while the underlying regulatory mechanism remains poorly understood. In this study, METTL14 was found to be upregulated in DTX-resistant PCa cells and PCa tissues exhibiting progressive disease during DTX therapy. Furthermore, overexpression of METTL14 promoted the development of resistance to DTX in both in vitro and in vivo. Interestingly, it was observed that the hypermethylation of the E2F1 targeting site within DTX-resistant PCa cells hindered the binding ability of E2F1 to the promoter region of METTL14, thereby augmenting its transcriptional activity. Consequently, this elevated expression level of METTL14 facilitated m6A-dependent processing of pri-miR-129 and subsequently led to an increase in miR-129-5p expression. Our study highlights the crucial role of the E2F1-METTL14-miR-129-5p axis in modulating DTX resistance in PCa, underscoring METTL14 as a promising therapeutic target for DTX-resistant PCa patients.


Assuntos
Antineoplásicos , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Epigênese Genética , Metiltransferases , MicroRNAs , Neoplasias da Próstata , MicroRNAs/genética , MicroRNAs/metabolismo , Masculino , Docetaxel/farmacologia , Humanos , Neoplasias da Próstata/genética , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Epigênese Genética/efeitos dos fármacos , Linhagem Celular Tumoral , Metiltransferases/genética , Metiltransferases/metabolismo , Animais , Antineoplásicos/farmacologia , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos Nus
7.
bioRxiv ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38328239

RESUMO

Fluid flow transport through the trabecular meshwork tissues is a major regulator of intraocular pressure (IOP) modulation in healthy and glaucomatous individuals. Microbead occlusion models of ocular hypertension regulate aqueous humor drainage to induce high IOP to allow for in vivo study of pressure-related glaucomatous pathology. However, the reliability and application of current injectable microbeads are hindered by inadequate design of the beads-tissue interfaces to maintain a stable IOP elevation over the long term. Considering the graded, porous architecture and fluid transport of the trabecular meshwork, we developed a tailored, injectable "viscobeads" technique, which induced a sustained elevation of IOP for at least 8 weeks. These composite viscobeads contain a non-degradable polystyrene (PS) core for structural support and a biodegradable polylactic-co-glycolic acid (PLGA) viscoelastic surface. This approach enhances the obstruction of aqueous humor drainage through heterogeneous sizes of trabecular meshwork fenestrations and reliably modulates the magnitude and duration of ocular hypertension. In a mouse model, a single viscobeads injection resulted in sustained IOP elevation (average 21.4±1.39 mm Hg), leading to a 34% retinal ganglion cell (RGC) loss by 56 days. In an earlier stage of glaucoma progression, we conducted non-invasive electroretinography (ERG) recording and revealed glaucomatous progression by analyzing high-frequency oscillatory potentials. To further explore the application of the viscobeads glaucoma models, we assayed a series of genes through adeno-associated virus (AAV)-mediated screening in mice and assessed the impact of genetic manipulation on RGC survivals. CRISPR mediated disruption of the genes, PTEN, ATF3 and CHOP enhanced RGC survival while LIN 28 disruption negatively impacted RGC survival. This biologically driven viscobeads design provides an accessible approach to investigate chronic intraocular hypertension and glaucoma-like neurodegeneration and ultimately tenders the opportunity to evaluate genetic and pharmacological therapeutics.

8.
Cell Mol Life Sci ; 81(1): 67, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38289345

RESUMO

Skeletal muscle is a highly specialized tissue composed of myofibres that performs crucial functions in movement and metabolism. In response to external stimuli and injuries, a range of stem/progenitor cells, with muscle stem cells or satellite cells (MuSCs) being the predominant cell type, are rapidly activated to repair and regenerate skeletal muscle within weeks. Under normal conditions, MuSCs remain in a quiescent state, but become proliferative and differentiate into new myofibres in response to injury. In addition to MuSCs, some interstitial progenitor cells (IPCs) such as fibro-adipogenic progenitors (FAPs), pericytes, interstitial stem cells expressing PW1 and negative for Pax7 (PICs), muscle side population cells (SPCs), CD133-positive cells and Twist2-positive cells have been identified as playing direct or indirect roles in regenerating muscle tissue. Here, we highlight the heterogeneity, molecular markers, and functional properties of these interstitial progenitor cells, and explore the role of muscle stem/progenitor cells in skeletal muscle homeostasis, aging, and muscle-related diseases. This review provides critical insights for future stem cell therapies aimed at treating muscle-related diseases.


Assuntos
Músculo Esquelético , Células-Tronco , Homeostase , Adipogenia
9.
Mol Neurobiol ; 61(2): 971-981, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37672148

RESUMO

Transcription factors are essential for the development and regeneration of the nervous system. The current study investigated key regulatory transcription factors in rat spinal cord development via RNA sequencing. The hub gene Ets1 was highly expressed in the spinal cord during the embryonic period, and then its expression decreased during spinal cord development. Knockdown of Ets1 significantly increased the axonal growth of cultured spinal cord neurons. Luciferase reporter assays and chromatin immunoprecipitation assays indicated that Ets1 could directly bind to the Lcn2 promoter and positively regulate Lcn2 transcription. In conclusion, these findings provide the first direct evidence that Ets1 regulates axon growth by controlling Lcn2 expression, and Ets1 may be a novel therapeutic target for axon regeneration in the central nervous system.


Assuntos
Axônios , Fatores de Transcrição , Animais , Ratos , Axônios/metabolismo , Regulação da Expressão Gênica , Regeneração Nervosa , Neurônios/metabolismo , Fatores de Transcrição/metabolismo
10.
J Periodontal Res ; 59(1): 162-173, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37905727

RESUMO

OBJECTIVE: The purpose of this study was to investigate resveratrol's specific role as an anti-inflammatory and osteogenic differentiation of hPDLSCs in periodontitis and to reveal the mechanisms involved. BACKGROUND: Numerous studies have shown that inhibiting the inflammatory response of periodontal tissues and promoting the regeneration of alveolar bone are crucial treatments for periodontitis. Resveratrol has been found to have certain anti-inflammatory property. However, the anti-inflammatory mechanism and osteogenic effect of resveratrol in periodontitis are poorly understood. MATERIALS AND METHODS: We constructed an in vitro periodontitis model by LPS stimulation of hPDLSCs and performed WB, RT-qPCR, and immunofluorescence to analyze inflammatory factors and related pathways. In addition, we explored the osteogenic ability of resveratrol in in vitro models. RESULTS: In vitro, resveratrol ameliorated the inflammatory response associated with activation of the NF-κB pathway through activation of the NRF2/HO-1 pathway, characterized by inhibition of p65/p50 nuclear translocation and the proinflammatory cytokines interleukin-1ß levels. Resveratrol also has a positive effect on osteogenic differentiation. CONCLUSIONS: Observations suggest that resveratrol modulates the inflammatory response in hPDLSCs via the NRF2/HO-1 and NF-κB pathways and promotes osteogenic differentiation.


Assuntos
NF-kappa B , Periodontite , Humanos , NF-kappa B/metabolismo , Resveratrol/farmacologia , Fator 2 Relacionado a NF-E2 , Osteogênese , Ligamento Periodontal , Anti-Inflamatórios/farmacologia , Diferenciação Celular , Células Cultivadas
11.
Neural Regen Res ; 19(8): 1812-1821, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38103248

RESUMO

JOURNAL/nrgr/04.03/01300535-202408000-00035/figure1/v/2023-12-16T180322Z/r/image-tiff Exosomes exhibit complex biological functions and mediate a variety of biological processes, such as promoting axonal regeneration and functional recovery after injury. Long non-coding RNAs (lncRNAs) have been reported to play a crucial role in axonal regeneration. However, the role of the lncRNA-microRNA-messenger RNA (mRNA)-competitive endogenous RNA (ceRNA) network in exosome-mediated axonal regeneration remains unclear. In this study, we performed RNA transcriptome sequencing analysis to assess mRNA expression patterns in exosomes produced by cultured fibroblasts (FC-EXOs) and Schwann cells (SC-EXOs). Differential gene expression analysis, Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, and protein-protein interaction network analysis were used to explore the functions and related pathways of RNAs isolated from FC-EXOs and SC-EXOs. We found that the ribosome-related central gene Rps5 was enriched in FC-EXOs and SC-EXOs, which suggests that it may promote axonal regeneration. In addition, using the miRWalk and Starbase prediction databases, we constructed a regulatory network of ceRNAs targeting Rps5, including 27 microRNAs and five lncRNAs. The ceRNA regulatory network, which included Ftx and Miat, revealed that exsosome-derived Rps5 inhibits scar formation and promotes axonal regeneration and functional recovery after nerve injury. Our findings suggest that exosomes derived from fibroblast and Schwann cells could be used to treat injuries of peripheral nervous system.

12.
Small ; 20(22): e2308851, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38112252

RESUMO

Vanadium oxides have aroused attention as cathode materials in aqueous zinc-ion batteries (AZIBs) due to their low cost and high safety. However, low ion diffusion and vanadium dissolution often lead to capacity decay and deteriorating stability during cycling. Herein, vanadium dioxides (VO2) nanobelts are coated with a single-atom cobalt dispersed N-doped carbon (Co-N-C) layer via a facile calcination strategy to form Co-N-C layer coated VO2 nanobelts (VO2@Co-N-C NBs) for cathodes in AZIBs. Various in-/ex situ characterizations demonstrate the interfaces between VO2 layers and Co-N-C layers can protect the VO2 NBs from collapsing, increase ion diffusion, and enhance the Zn2+ storage performance. Additional density functional theory (DFT) simulations demonstrate that Co─O─V bonds between VO2 and Co-N-C layers can enhance interfacial Zn2+ storage. Moreover, the VO2@Co-N-C NBs provided an ultrahigh capacity (418.7 mAh g-1 at 1 A g-1), outstanding long-term stability (over 8000 cycles at 20 A g-1), and superior rate performance.

13.
Bioact Mater ; 33: 572-590, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38111651

RESUMO

A central question in neural tissue engineering is how the tissue-engineered nerve (TEN) translates detailed transcriptional signals associated with peripheral nerve regeneration into meaningful biological processes. Here, we report a skin-derived precursor-induced Schwann cell (SKP-SC)-mediated chitosan/silk fibroin-fabricated tissue-engineered nerve graft (SKP-SCs-TEN) that can promote sciatic nerve regeneration and functional restoration nearly to the levels achieved by autologous nerve grafts according to behavioral, histological, and electrophysiological evidence. For achieving better effect of neuroregeneration, this is the first time to jointly apply a dynamic perfusion bioreactor and the ascorbic acid to stimulate the SKP-SCs secretion of extracellular matrix (ECM). To overcome the limitation of traditional tissue-engineered nerve grafts, jointly utilizing SKP-SCs and their ECM components were motivated by the thought of prolongating the effect of support cells and their bioactive cues that promote peripheral nerve regeneration. To further explore the regulatory model of gene expression and the related molecular mechanisms involved in tissue engineering-aided peripheral nerve regeneration, we performed a cDNA microarray analysis of gene expression profiling, a comprehensive bioinformatics analysis and a validation study on the grafted segments and dorsal root ganglia tissues. A wealth of transcriptomic and bioinformatics data has revealed complex molecular networks and orchestrated functional regulation that may be responsible for the effects of SKP-SCs-TEN on promoting peripheral nerve regeneration. Our work provides new insights into transcriptomic features and patterns of molecular regulation in nerve functional recovery aided by SKP-SCs-TEN that sheds light on the broader possibilities for novel repair strategies of peripheral nerve injury.

14.
Mol Biol Rep ; 51(1): 9, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38085347

RESUMO

BACKGROUND: Complex pathophysiological changes accompany denervation-induced skeletal muscle atrophy, but no effective treatment strategies exist. Our previous study indicated that extracellular vesicles derived from skin-derived precursors-derived Schwann cells (SKP-SC-EVs) can effectively mitigate denervation-induced muscle atrophy. However, the specific molecular mechanism remains unclear. METHODS AND RESULTS: In this study, we used bioinformatics methods to scrutinize the impact of SKP-SC-EVs on gene expression in denervation-induced skeletal muscle atrophy. We found that SKP-SC-EVs altered the expression of 358 genes in denervated skeletal muscles. The differentially expressed genes were predominantly participated in biological processes, including cell cycle, inflammation, immunity, and adhesion, and signaling pathways, such as FoxO and PI3K.Using the Molecular Complex Detection (MCODE) plugin, we identified the two clusters with the highest score: cluster 1 comprised 37 genes, and Cluster 2 consisted of 24 genes. Then, fifty hub genes were identified using CytoHubba. The intersection of Hub genes and genes obtained by MCODE showed that all 23 genes related to the cell cycle in Cluster 1 were hub genes, and 5 genes in Cluster 2 were hub genes and associated with inflammation. CONCLUSIONS: Overall, the differentially expressed genes in denervated skeletal muscle following SKP-SC-EVs treatment are primarily linked to the cell cycle and inflammation. Consequently, promoting proliferation and inhibiting inflammation may be the critical process in which SKP-SC-EVs delay denervation-induced muscle atrophy. Our findings contribute to a better understanding of the molecular mechanism of SKP-SC-EVs delaying denervation-induced muscle atrophy, offering a promising new avenue for muscle atrophy treatment.


Assuntos
Atrofia Muscular , Transcriptoma , Humanos , Atrofia Muscular/genética , Atrofia Muscular/metabolismo , Músculo Esquelético/metabolismo , Denervação , Inflamação/metabolismo
15.
Curr Med Chem ; 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37885109

RESUMO

As the number of viruses, bacteria, and tumors that are resistant to drugs continues to rise, there is a growing need for novel lead compounds to treat them. Marine fungi, due to their unique secondary metabolic pathways and vast biodiversity, have become a crucial source for lead compounds in drug development. This review utilizes bibliometric methods to analyze the research status of natural products from marine fungi in the past decade, revealing the hotspots and trends in this field from Web of Science database. Furthermore, this review summarizes the biological activities and effects on molecular mechanisms of novel natural compounds isolated from marine fungi in the past five years. These novel compounds belong to six different structural classes, such as alkaloids, terpenoids, anthraquinones, polyketones, etc. They also exhibited highly potent biological properties, including antiviral, antitumor, antibacterial, antiinflammatory, and other properties. This review demonstrates the hotspots and trends of marine fungi research in recent years, as well as the variety of chemical structure and biological activities of their natural products, and it may provide guidance for those interested in discovering new drugs from marine fungi and specific targeting mechanisms.

16.
Elife ; 122023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37535403

RESUMO

A key limiting factor of successful axon regeneration is the intrinsic regenerative ability in both the peripheral nervous system (PNS) and central nervous system (CNS). Previous studies have identified intrinsic regenerative ability regulators that act on gene expression in injured neurons. However, it is less known whether RNA modifications play a role in this process. Here, we systematically screened the functions of all common m6A modification-related enzymes in axon regeneration and report ALKBH5, an evolutionarily conserved RNA m6A demethylase, as a regulator of axonal regeneration in rodents. In PNS, knockdown of ALKBH5 enhanced sensory axonal regeneration, whereas overexpressing ALKBH5 impaired axonal regeneration in an m6A-dependent manner. Mechanistically, ALKBH5 increased the stability of Lpin2 mRNA and thus limited regenerative growth associated lipid metabolism in dorsal root ganglion neurons. Moreover, in CNS, knockdown of ALKBH5 enhanced the survival and axonal regeneration of retinal ganglion cells after optic nerve injury. Together, our results suggest a novel mechanism regulating axon regeneration and point ALKBH5 as a potential target for promoting axon regeneration in both PNS and CNS.


Nerve cells, or neurons, are the key communication components of the body. Each neuron takes signals from many inputs and transmits them through a single output called the axon. In the central nervous system, which consists of the brain and spinal cord, damaged neurons do not generally repair themselves. But in the peripheral nervous system, where neurons branch out to other parts of the body, they can regenerate. For this to happen, genes which promote axon regrowth must be expressed. Messenger RNA carries DNA information from the nucleus of a cell to the cytoplasm where it serves as instructions for generating proteins. Certain enzymes can modify messenger RNA, changing how long it lasts, where it goes in the cell and what proteins it makes. It has been suggested that a particular RNA modification, known as m6A, plays an important role in axon regrowth as increased m6A levels have been reported in some neurons after a peripheral nerve injury. Wang et al. studied the impact of m6A modifications on axon regrowth by examining the effects of several genes associated with these modifications in rats. The experiments showed that expression of a gene called Alkbh5 ­ which codes for an enzyme that removes m6A modifications ­ regulates the amount of axon regrowth following an injury to peripheral nerves. Reducing the amount of Alkbh5 expression rates increased axon regrowth, whereas in rats where Alkbh5 was overexpressed, regrowth was reduced. Further experiments showed that the ALKBH5 enzyme helps to make mRNA from the gene Lpin2 more stable, which affects how it processes fats and lipids during the regeneration process. Moreover, in the central nervous system, reducing Alkbh5 expression enhanced survival and axon regrowth of neurons in the eye after they were injured in mice. The findings suggest that Alkbh5 influences axon regrowth and are an important step towards understanding how biological systems repair nerve damage. Future work should investigate if stopping Alkbh5 expression allows injured neurons to recover their function and how different m6A-associated enzymes work together in this process.


Assuntos
Axônios , Regeneração Nervosa , Axônios/fisiologia , Regeneração Nervosa/genética , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Gânglios Espinais/metabolismo , Células Ganglionares da Retina , RNA/metabolismo
17.
Curr Med Chem ; 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37605398

RESUMO

Marine natural products have great pharmacological potential due to their unique and diverse chemical structures. The marine bacterial biodiversity and the unique marine environment lead to a high level of complexity and ecological interaction among marine species. This results in the production of metabolic pathways and adaptation mechanisms that are different from those of terrestrial organisms, which has drawn significant attention from researchers in the field of natural medicine. This review provides an analysis of the distribution and frequency of keywords in the literature on marine bacterial natural products as well as an overview of the new natural products isolated from the secondary metabolites of marine bacteria in recent years. Finally, it discusses the current research hotspots in this field and speculates on future directions and limitations.

18.
iScience ; 26(8): 107264, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37502257

RESUMO

Spinal motor neurons, the distinctive neurons of the central nervous system, extend into the peripheral nervous system and have outstanding ability of axon regeneration after injury. Here, we explored the heterogeneity of spinal ventral horn cells after rat sciatic nerve crush via single-nuclei RNA sequencing. Interestingly, regeneration mainly occurred in a Sncg+ and Anxa2+ motor neuron subtype (MN2) surrounded by a newly emerged microglia subtype (Mg6) after injury. Subsequently, microglia depletion slowed down the regeneration of sciatic nerve. OPCs were also involved into the regeneration process. Knockdown of Cacna2d2 in vitro and systemic blocking of Cacna2d2 in vivo improved the axon growth ability, hinting us the importance of Ca2+. Ultimately, we proposed three possible phases of motor neuron axon regeneration: preparation stage, early regeneration stage, and regeneration stage. Taken together, our study provided a resource for deciphering the underlying mechanism of motor neuron axon regeneration in a single cell dimension.

19.
Forensic Sci Int ; 349: 111776, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37399775

RESUMO

Because of its hallucinogenic and dissociative effects, ketamine is often abused for recreational purposes. Thus, the seizure of ketamine manufacturing units is crucial for preventing drug abuse. The precursors popularly used for ketamine synthesis include 1-[(2-chlorophenyl)(methylimino)methyl]cyclopentanol hydrochloride and 2-(2-chlorophenyl)-2-nitrocyclohexanone (2-CPNCH). Herein, we report a case of the seizure of a ketamine manufacturing unit by law enforcement officers. The seized materials were sent to our laboratory for confirmation. We found that 2-CPNCH was used as the precursor. Using zinc powder and formic acid, 2-CPNCH was reduced to norketamine. Through the Eschweiler-Clarke reaction, norketamine was reacted with formaldehyde and formic acid to synthesize ketamine; the advantages of this process are a short duration of reaction and the requirement of small amounts of chemicals. We further identified an impurity (N-methyl ketamine), which was used as a marker to validate this new process of ketamine synthesis. To the best of our knowledge, this study is the first to report illegal ketamine synthesis through the Eschweiler-Clarke reaction when using 2-CPNCH as the precursor. Our findings inform law enforcement officers and forensic practitioners about this new process of ketamine synthesis.

20.
Mol Med ; 29(1): 79, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37365519

RESUMO

BACKGROUND: Myelin sheath is a crucial accessory to the functional nerve-fiber unit, its disruption or loss can lead to axonal degeneration and subsequent neurodegenerative diseases (NDs). Notwithstanding of substantial progress in possible molecular mechanisms underlying myelination, there is no therapeutics that prevent demyelination in NDs. Therefore, it is crucial to seek for potential intervention targets. Here, we focused on the transcriptional factor, signal transducer and activator of transcription 1 (Stat1), to explore its effects on myelination and its potential as a drug target. METHODS: By analyzing the transcriptome data obtained from Schwann cells (SCs) at different stages of myelination, it was found that Stat1 might be involved in myelination. To test this, we used the following experiments: (1) In vivo, the effect of Stat1 on remyelination was observed in an in vivo myelination mode with Stat1 knockdown in sciatic nerves or specific knockdown in SCs. (2) In vitro, the RNA interference combined with cell proliferation assay, scratch assay, SC aggregate sphere migration assay, and a SC differentiation model, were used to assess the effects of Stat1 on SC proliferation, migration and differentiation. Chromatin immunoprecipitation sequencing (ChIP-Seq), RNA-Seq, ChIP-qPCR and luciferase activity reporter assay were performed to investigate the possible mechanisms of Stat1 regulating myelination. RESULTS: Stat1 is important for myelination. Stat1 knockdown in nerve or in SCs reduces the axonal remyelination in the injured sciatic nerve of rats. Deletion of Stat1 in SCs blocks SC differentiation thereby inhibiting the myelination program. Stat1 interacts with the promoter of Rab11-family interacting protein 1 (Rab11fip1) to initiate SC differentiation. CONCLUSION: Our findings demonstrate that Stat1 regulates SC differentiation to control myelinogenic programs and repair, uncover a novel function of Stat1, providing a candidate molecule for clinical intervention in demyelinating diseases.


Assuntos
Bainha de Mielina , Fator de Transcrição STAT1 , Células de Schwann , Animais , Ratos , Axônios , Diferenciação Celular , Regeneração Nervosa , Células de Schwann/metabolismo , Nervo Isquiático , Fator de Transcrição STAT1/metabolismo
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