Despite recent advances in understanding the biology of aging,the field remains fragmented due to the lack of a central organizing hypothesis.Although there are ongoing debates on whether the aging process is programmed or stochastic,it is now evident that neither perspective alone can fully explain the complexity of aging.Here,we propose the pro-aging metabolic reprogramming(PAMRP)theory,which integrates and unifies the genetic-program and stochastic hypotheses.This theory posits that aging is driven by degenerative metabolic reprogramming(MRP)over time,requiring the emergence of pro-aging substrates and triggers(PASs and PATs)to predispose cells to cellular and genetic reprogramming(CRP and GRP).
Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness remains unsatisfactory.However,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming.In this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic reprogramming.Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling.However,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial dysfunction.These metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of microglia.To rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell fate.The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury.To further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions.
Müller glia,as prominent glial cells within the retina,plays a significant role in maintaining retinal homeostasis in both healthy and diseased states.In lower vertebrates like zebrafish,these cells assume responsibility for spontaneous retinal regeneration,wherein endogenous Müller glia undergo proliferation,transform into Müller glia-derived progenitor cells,and subsequently regenerate the entire retina with restored functionality.Conversely,Müller glia in the mouse and human retina exhibit limited neural reprogramming.Müller glia reprogramming is thus a promising strategy for treating neurodegenerative ocular disorders.Müller glia reprogramming in mice has been accomplished with remarkable success,through various technologies.Advancements in molecular,genetic,epigenetic,morphological,and physiological evaluations have made it easier to document and investigate the Müller glia programming process in mice.Nevertheless,there remain issues that hinder improving reprogramming efficiency and maturity.Thus,understanding the reprogramming mechanism is crucial toward exploring factors that will improve Müller glia reprogramming efficiency,and for developing novel Müller glia reprogramming strategies.This review describes recent progress in relatively successful Müller glia reprogramming strategies.It also provides a basis for developing new Müller glia reprogramming strategies in mice,including epigenetic remodeling,metabolic modulation,immune regulation,chemical small-molecules regulation,extracellular matrix remodeling,and cell-cell fusion,to achieve Müller glia reprogramming in mice.
Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Nanoscale perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory properties.However,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly understood.In this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s disease.Microglial suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in vitro.Consequently,the neurotoxic effects were mitigated,which alleviated neuronal degeneration.Additionally,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic reprogramming.We further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1αpathway.Collectively,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.
Wanxian LuoChuanhui XuLinxi LiYunxiang JiYezhong WangYingjia LiYongyi Ye
Dear Editor,Epigenetic programming plays a critical role in response to environmental fluctuations in eukaryotes(Jaenisch and Bird,2003).From initial contact to successful colonization,pathogenic microorganisms adeptly adapt to environmental changes by orchestrating a cascade of gene expression.However,how plant pathogens adapt to the host environment during early infection at the epigenetic level is largely elusive.
Tumorigenesis is usually accompanied by changes in metabolic patterns,known as metabolic reprogramming[1].To meet the overall metabolic needs for tumor growth and development,tumors regulate the metabolic processes of different cell types by exploiting various environmental and nutritional conditions[2].The metabolic reprogramming of various human tumors is largely conservative[3].However,substantial heterogeneity complicates the identification of their internal causes and mechanisms.Transcriptomics can comprehensively measure tumor metabolism indirectly[4-6].Metabolic reprogramming studies of single cells in various cancer types based on scRNA-seq can reveal their internal networks with other cancer determinants.
Background:The inability of damaged neurons to regenerate and of axons to estab-lish new functional connections leads to permanent functional deficits after spinal cord injury(SCI).Although astrocyte reprogramming holds promise for neurorepair in various disease models,it is not sufficient on its own to achieve significant functional recovery.Methods:A rat SCI model was established using a spinal cord impactor.Seven days postsurgery,adeno-associated virus were injected to overexpress the transcription factors NeuroD1 and Neurogenin-2(Ngn2)in the spinal cord.The rats were then trained to walk on a weight-supported treadmill for 4 weeks,starting 14 days after modeling.The effects of these interventions on motor and sensory functions,as well as spinal cord tissue repair,were subsequently evaluated.Results:The combination of NeuroD1 and Ngn2 overexpression with weight-supported exercise training significantly improved gait compared to either inter-vention alone.The group receiving the combined intervention exhibited enhanced sensitivity in sensory assessments.Immunofluorescence analysis revealed increased colocalization of astrocytes and microtubule-associated protein 2-positive neurons in the injury area.These effects were more pronounced than those observed with spinal cord tissue repair alone.Additionally,the combined intervention significantly reduced glial scarring and the size of the injury area.Conclusion:Exercise intervention enhances the reprogramming effects of astrocytes and restores motor function,yielding better results than either intervention alone.
Centella asiatica L.,a medicinal herb,has attracted substantial interest in research as well as commercial domains due to its bioactive compounds which include the pentacyclic triterpenoid centellosides,and in addition,hydroxy.In addition,hydroxycinnamic acid conjugates as well as flavonoids.The latter is the major class of secondary plant metabolites and comprises various subclasses,including anthocyanidins.Anthocyanins are rarely reported in extracts from C.asiatica and differ structurally due to a flavylium(2-phenylchromenylium)ion that carries a positive charge at the oxygen atom of the C-ring of the basic flavonoid structure.Callus of C.asiatica was initiated and propagated on synthetic media and subjected to different light regimes.White callus resulted from white fluorescent illumination,while purple callus developed in response to white light emitting diode(LED)illumination.To profile the metabolites responsible for the intense purple coloration,methanolic extracts were prepared from the two cell lines.Total phenolic,flavonoid,and anthocyanin content were determined and indicated(i)very low levels of flavonoids and anthocyanins in white callus and(ii)that anthocyanins dominate the flavonoid content of the purple callus.Extracts were subjected to untargeted ultra-high-performance liquid chromatography coupled to high-definition mass spectrometry(UHPLC–MS)to profile newly synthesized anthocyanins.Metabolite annotation was based on accurate mass determination and characteristic fragmentation patterns.Here,the reprogramming of the metabolome of white C.asiatica callus due to LED illumination is reported and the profiles of cryptic anthocyanins as well as putative flavonoid and caffeoylquinic acid co-pigments in purple callus are described.
Claude Y.Hamany DjandePaul A.SteenkampIan A.Dubery
The neonatal mammalian heart has a remarkable regenerative capacity,while the adult heart has difficulty to regenerate.A metabolic reprogramming from glycolysis to fatty acid oxidation occurs along with the loss of cardiomyocyte proliferative capacity shortly after birth.In this study,we sought to determine if and how metabolic reprogramming regulates cardiomyocyte proliferation.Reversing metabolic reprogramming by carnitine palmitoyltransferase 1(CPT1)inhibition,using cardiac-specific Cpt1a and Cpt1b knockout mice promoted cardiomyocyte proliferation and improved cardiac function post-myocardial infarction.The inhibition of CPT1 is of pharmacological significance because those protective effects were replicated by etomoxir,a CPT1 inhibitor.CPT1 inhibition,by decreasing poly(ADP-ribose)polymerase 1 expression,reduced ADP-ribosylation of dual-specificity phosphatase 1 in cardiomyocytes,leading to decreased p38 MAPK phosphorylation,and stimulation of cardiomyocyte proliferation.Our present study indicates that reversing metabolic reprogramming is an effective strategy to stimulate adult cardiomyocyte proliferation.CPT1 is a potential therapeutic target for promoting heart regeneration and myocardial infarction treatment.
Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative medicine.The brea kth rough discovery that induced pluripotent stem cells could be generated from adult mouse fibroblasts is powerful proof that cell fate can be changed.An exciting extension of the discovery of cell fate impermanence is the direct cellular reprogram ming hypothesis-that terminally differentiated cells can be reprogrammed into other adult cell fates without first passing through a stem cell state.
