Proliferation

摘要： Astrocytes and microglia play an orchestrated role following spinal cord injury;however,the molecular mechanisms through which microglia regulate astrocytes after spinal cord injury are not yet fully understood.Herein,microglia were pharmacologically depleted and the effects on the astrocytic response were examined.We further explored the potential mechanisms involving the signal transducers and activators of transcription 3(STAT3)pathway.For in vivo experiments,we constructed a contusion spinal cord injury model in C57BL/6 mice.To deplete microglia,all mice were treated with colony-stimulating factor 1 receptor inhibitor PLX3397,starting 2 weeks prior to surgery until they were sacrificed.Cell proliferation was examined by 5-ethynyl-2-deoxyuridine(EdU)and three pivotal inflammatory cytokines were detected by a specific Bio-Plex ProTM Reagent Kit.Locomotor function,neuroinflammation,astrocyte activation and phosphorylated STAT3(pSTAT3,a maker of activation of STAT3 signaling)levels were determined.For in vitro experiments,a microglia and astrocyte coculture system was established,and the small molecule STA21,which blocks STAT3 activation,was applied to investigate whether STAT3 signaling is involved in mediating astrocyte proliferation induced by microglia.PLX3397 administration disrupted glial scar formation,increased inflammatory spillover,induced diffuse tissue damage and impaired functional recovery after spinal cord injury.Microglial depletion markedly reduced EdU+proliferating cells,especially proliferating astrocytes at 7 days after spinal cord injury.RNA sequencing analysis showed that the JAK/STAT3 pathway was downregulated in mice treated with PLX3397.Double immunofluorescence staining confirmed that PLX3397 significantly decreased STAT3 expression in astrocytes.Importantly,in vitro coculture of astrocytes and microglia showed that microglia-induced astrocyte proliferation was abolished by STA21 administration.These findings suggest that microglial depletion impaired astrocyte proliferation and astrocytic scar formation,and induced inflammatory diffusion partly by inhibiting STAT3 phosphorylation in astrocytes following spinal cord injury.

摘要： Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.

摘要： The extracellular matrix surrounding oligodendrocytes plays an important role during myelination and remyelination in the brain.In many cases,the microenvironment surrounding demyelination lesions contains inhibitory molecules,which lead to repair failure.Accordingly,blocking the activity of these inhibitory factors in the extracellular matrix should lead to more successful remyelination.In the central nervous system,oligodendrocytes form the myelin sheath.We performed primary cell culture and found that a natural increase in fibronectin promoted the proliferation of oligodendrocyte progenitors during the initial stage of remyelination while inhibiting oligodendrocyte differentiation.Poly-L-ornithine blocked these inhibitory effects without compromising fibronectin’s pro-proliferation function.Experiments showed that poly-L-ornithine activated the Erk1/2 signaling pathway that is necessary in the early stages of differentiation,as well as PI3K signaling pathways that are needed in the mid-late stages.When poly-L-ornithine was tested in a lysolecithin-induced animal model of focal demyelination,it enhanced myelin regeneration and promoted motor function recovery.These findings suggest that poly-L-ornithine has the potential to be a treatment option for clinical myelin sheath injury.

摘要： Background:Ursolic acid is a triterpenoid compound found in natural plants that exhibits antiproliferative effects in various cancer cells.Our study is the first to demonstrate the strong inhibitory effects of ursolic acid on the proliferation of cutaneous T-cell lymphoma(CTCL)cells.We aimed to further investigate the underlying mechanism of the proliferation inhibition induced by ursolic acid in CTCL cells using transcriptome sequencing.Methods:Cell counting kit-8 assays were used to observe the effects of six traditional medicine monomers on the proliferation of CTCL cells.Transcriptome sequencing was used to identify differentially expressed genes after ursolic acid treatment.Bioinformatics analysis was performed to determine the potential mechanism.Real-time quantitative PCR and western blotting analyses were performed to confirm the sequencing results and verify the possible mechanisms of ursolic acid-mediated proliferation inhibition in CTCL cells.Results:Ursolic acid exhibited the strongest inhibitory effect on the proliferation of CTCL cells among the six traditional medicine monomers.Transcriptome sequencing analysis showed that 2,466 genes were significantly altered.Combined with Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis and protein-protein interaction network analysis,the interaction of various pathways and signaling molecules,such as tumor necrosis factor-α,NLR family pyrin domain containing 1,c-Jun N-terminal kinase,and melanoma differentiation-associated gene 5,accounted for the anti-tumor effects of ursolic acid in CTCL cells.Conclusion:Ursolic acid significantly inhibited the proliferation of CTCL cells,and our study laid a theoretical foundation for the future treatment of CTCL using ursolic acid.

摘要： Chronic high glucose(HG) plays a crucial role in the pathogenesis of diabetes-induced osteoporosis by inhibiting the differentiation and proliferation of osteoblasts. This study aims to examine the role of E26 transformation-specific 1(ETS1) in the inhibition of osteoblast differentiation and proliferation caused by chronic HG, as well as the underlying mechanism. Chronic HG treatment downregulated ETS1 expression and inhibited differentiation and proliferation of MC3 T3-E1 cells. Downregulation of ETS1 expression inhibited the differentiation and proliferation of MC3 T3-E1 cells under normal glucose conditions, and ETS1 overexpression attenuated the damage to cells exposed to chronic HG. In addition, ETS1 overexpression reversed the decrease in runt-related transcription factor 2(Runx2) expression in MC3 T3-E1 cells treated with chronic HG. Using chromatin immunoprecipitation(ChIP) and luciferase reporter assays, we confirmed that ETS1 directly bound to and increased the activity of the Runx2 promoter. In summary, our study suggested that ETS1 was involved in the inhibitory effect of chronic HG on osteogenic differentiation and proliferation and may be a potential therapeutic target for diabetes-induced osteoporosis.

摘要： Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and chara cterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitte rs that mediate many diverse cellular processes within the central nervous system.While our unde rstanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.

摘要： An RNA-binding protein,LIN28A was initially discovered in nematodes Caenorhabditis elegans and regulated stem cell differentiation and proliferation.With the aid of mouse models and cancer stem cells models,LIN28A demonstrated a similar role in mammalian stem cells.Subsequent studies revealed LIN28A’s roles in regulating cell cycle and growth,tissue repair,and metabolism,especially glucose metabolism.Through regulation by pluripotency and neurotrophic factors,LIN28A performs these roles through let-7 dependent(binding to let-7)or independent(binding directly to mature mRNA)pathways.Elevated LIN28A levels are associated with cancers such as breast,colon,and ovarian cancers.Overexpressed LIN28A has been implicated in liver diseases and Rett syndrome whereas loss of LIN28A was linked to Parkinson’s disease.LIN28A inhibitors,LIN28A-specific nanobodies,and deubiquitinases targeting LIN28A could be feasible options for cancer treatments while drugs upregulating LIN28A could be used in regenerative therapy for neuropathies.We will review the upstream and downstream signalling pathways of LIN28A and its physiological functions.Then,we will examine current research and gaps in research regarding its mechanisms in conditions such as cancers,liver diseases,and neurological diseases.We will also look at the therapeutic potential of LIN28A in RNA-targeted therapies including small interfering RNAs and RNAprotein interactions.

摘要： BACKGROUND Diabetic cardiomyopathy(DCM) is a serious complication of end-stage diabetes that presents symptoms such as cardiac hypertrophy and heart failure. The transient receptor potential channel 6(TRPC6) protein is a very important selective calcium channel that is closely related to the development of various cardiomyopathies.AIM To explore whether TRPC6 affects cardiomyocyte apoptosis and proliferation inhibition in DCM.METHODS We compared cardiac function and myocardial pathological changes in wild-type mice and mice injected with streptozotocin(STZ), in addition to comparing the expression of TRPC6 and P-calmodulin-dependent protein kinase Ⅱ(P-CaMKⅡ) in them. At the same time, we treated H9C2 cardiomyocytes with high glucose and then evaluated the effects of addition of SAR, a TRPC6 inhibitor, and KN-93, a CaMKⅡ inhibitor, to such H9C2 cells in a high-glucose environment.RESULTS We found that STZ-treated mice had DCM, decreased cardiac function, necrotic cardiomyocytes, and limited proliferation. Western blot and immunofluorescence were used to detect the expression levels of various appropriate proteins in the myocardial tissue of mice and H9C2 cells. Compared to those in the control group, the expression levels of the apoptosis-related proteins cleaved caspase 3 and Bax were significantly higher in the experimental group, while the expression of the proliferation-related proteins proliferating cell nuclear antigen(PCNA) and CyclinD1 was significantly lower. In vivo and in vitro, the expression of TRPC6 and P-CaMKⅡ increased in a high-glucose environment. However, addition of inhibitors to H9C2 cells in a high-glucose environment resulted in alleviation of both apoptosis and proliferation inhibition.CONCLUSION The inhibition of apoptosis and proliferation of cardiomyocytes in a high-glucose environment may be closely related to activation of the TRPC6/P-CaMKⅡ pathway.

摘要： BACKGROUND Gastric carcinoma(GC)is a common gastrointestinal malignancy worldwide.Based on the cancer-related mortality,the current prevention and treatment strategies for GC still show poor clinical results.Therefore,it is important to find effective drug treatment targets.AIM To explore the mechanism by which 18β-glycyrrhetinic acid(18β-GRA)regulates mitochondrial ribosomal protein L35(MRPL35)related signal proteins to inhibit the proliferation of GC cells.METHODS Cell counting kit-8 assay was used to detect the effects of 18β-GRA on the survival rate of human normal gastric mucosal cell line GES-1 and the proliferation of GC cell lines MGC80-3 and BGC-823.The apoptosis and cell cycle were assessed by flow cytometry.Cell invasion and migration were evaluated by Transwell assay,and cell scratch test was used to detect cell migration.Furthermore,a tumor model was established by hypodermic injection of 2.5×106 BGC-823 cells at the selected positions of BALB/c nude mice to determine the effect of 18β-GRA on GC cell proliferation,and quantitative reverse transcription-polymerase chain reaction(qRT-PCR)was used to detect MRPL35 expression in the engrafted tumors in mice.We used the term tandem mass tag(TMT)labeling combined with liquid chromatography–tandem mass spectrometry to screen for differentially expressed proteins(DEPs)extracted from GC cells and control cells after 18β-GRA intervention.A detailed bioinformatics analysis of these DEPs was performed,including Gene Ontology annotation and enrichment analysis,Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis,and so on.Moreover,STRING database(https://string-db.org/)was used to predict proteinprotein interaction(PPI)relationships and Western blot was used to detect the expression of proteins of interest in GC cells.RESULTS The results indicated that 18β-GRA could inhibit the proliferation of GC cells in a dose-and timedependent manner.It could induce GC cell apoptosis and arrest the cell cycle at G0/G1 phase.The proportion of cells arrested at S phase decreased with the increase of 18-GRA dose,and the migration and invasiveness of GC cells were inhibited.The results of animal experiments showed that 18β-GRA could inhibit tumor formation in BALB/c nude mice,and qRT-PCR results showed that MRPL35 expression level was significantly reduced in the engrafted tumors in mice.Using TMT technology,609 DEPs,among which 335 were up-regulated and 274 were down-regulated,were identified in 18β-GRA intervention compared with control.We found that the intervention of 18β-GRA in GC cells involved many important biological processes and signaling pathways,such as cellular processes,biological regulation,and TP53 signaling pathway.Notably,after the drug intervention,MRPL35 expression was significantly down-regulated(P=0.000247),TP53 expression was up-regulated(P=0.02676),and BCL2L1 was down-regulated(P=0.01699).Combined with the Retrieval of Interacting Genes/Proteins database,we analyzed the relationship between MRPL35,TP53,and BCL2L1 signaling proteins,and we found that COPS5,BAX,and BAD proteins can form a PPI network with MRPL35,TP53,and BCL2L1.Western blot analysis confirmed the intervention effect of 18β-GRA on GC cells,MRPL35,TP53,and BCL2L1 showed dose-dependent up/down-regulation,and the expression of COPS5,BAX,and BAD also increased/decreased with the change of 18β-GRA concentration.CONCLUSION 18β-GRA can inhibit the proliferation of GC cells by regulating MRPL35,COPS5,TP53,BCL2L1,BAX,and BAD.

摘要： Objective:The aims of this study were to examine the prognostic value of SHP-1 in breast cancer,its roles in the regulation of breast cancer cell growth and metastasis,and the underlying mechanisms.Methods:Tumor specimens from 160 patients with breast cancer and 160 noncancerous tissues were used to examine the expression of SHP-1 and to analyze its association with overall survival through Kaplan–Meier and multivariate Cox regression analyses.RNA sequencing data and the expression and clinical importance of SHP-1 in breast cancer were evaluated with data from The Cancer Genome Atlas.In vitro and in vivo assays were performed to elucidate the effects of SHP-1 on breast cancer cell proliferation and invasion.Confocal immunofluorescence and GST pulldown assays were used to demonstrate the interaction between SHP-1 and epidermal growth factor receptor,as well as its downstream pathways.Immunohistochemistry and The Cancer Genome Atlas database were used to investigate the clinical association between SHP-1 and EGFR in human breast cancer.Results:SHP-1 expression was associated with better survival in patients with breast cancer,whereas SHP-1 expression was negatively correlated with EGFR in human breast cancer.Ectopic SHP-1 expression significantly suppressed breast cancer cell proliferation,migration,and invasion.SHP-1 knockdown induced a more invasive phenotype and accelerated cell growth.Mechanistically,EGFR,a protein directly interacting with SHP-1,mediates the SHP-1-induced inactivation of Ras/Erk/GSK3βsignaling and its downstream effectors.Conclusions:SHP-1 is an important prognostic biomarker in patients with breast cancer,and the SHP-1-EGFR axis is a promising target for treatment.