Point mutations of homologs as an adaptive solution to the gene loss

Gene loss is common and influences genome evolution trajectories.Multiple adaptive strategies to compensate for gene loss have been observed,including copy number gain of paralogous genes and mutations in genes of the same pathway.By using the Ubl-specific protease 2(ULP2)eviction model,we identify compensatory mutations in the homologous gene ULP1 by laboratory evolution and find that these mutations are capable of rescuing defects caused by the loss of ULP2.Furthermore,bioinformatics analysis of genomes of yeast gene knockout library and natural yeast isolate datasets suggests that point mutations of a homologous gene might be an additional mechanism to compensate for gene loss.

Dependence of impact regime boundaries on the initial temperatures of projectiles and targets

Towards higher impact velocities,ballistic events are increasingly determined by the material temperatures.Related effects might range from moderate thermal softening to full phase transition.In particular,it is of great interest to quantify the conditions for incipient or full melting of metals during impact interactions,which result in a transition from still strength-affected to hydrodynamic material behavior.In this work,we investigate to which extent the respective melting thresholds are also dependent on the initial,and generally elevated,temperatures of projectiles and targets before impact.This is studied through the application of a model developed recently by the authors to characterize the transition regime between high-velocity and hypervelocity impact,for which the melting thresholds of materials were used as the defining quantities.The obtained results are expected to be of general interest for ballistic application cases where projectiles or targets are preheated.Such conditions might result,for example,from aerodynamic forces acting onto a projectile during atmospheric flight,explosive shapedcharge-jet formation or armor exposure to environmental conditions.The performed analyses also broaden the scientific understanding of the relevance of temperature in penetration events,generally known since the 1960s,but often not considered thoroughly in impact studies.

Inhibiting SHP2 reduces glycolysis, promotes microglial M1 polarization, and alleviates secondary inflammation following spinal cord injury in a mouse model

Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.

Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

Mitochondrial carrier homolog 2 increases malignant phenotype of human gastric epithelial cells and promotes proliferation,invasion,and migration of gastric cancer cells

BACKGROUND The precise role of mitochondrial carrier homolog 2(MTCH2)in promoting malignancy in gastric mucosal cells and its involvement in gastric cancer cell metastasis have not been fully elucidated.AIM To determine the role of MTCH2 in gastric cancer.METHODS We collected 65 samples of poorly differentiated gastric cancer tissue and adjacent tissues,constructed MTCH2-overexpressing and MTCH2-knockdown cell models,and evaluated the proliferation,migration,and invasion of human gastric epithelial cells(GES-1)and human gastric cancer cells(AGS)cells.The mito-chondrial membrane potential(MMP),mitochondrial permeability transformation pore(mPTP)and ATP fluorescence probe were used to detect mitochondrial function.Mitochondrial function and ATP synthase protein levels were detected via Western blotting.RESULTS The expression of MTCH2 and ATP2A2 in gastric cancer tissues was significantly greater than that in adjacent tissues.Overexpression of MTCH2 promoted colony formation,invasion,migration,MMP expression and ATP production in GES-1 and AGS cells while upregulating ATP2A2 expression and inhibiting cell apoptosis;knockdown of MTCH2 had the opposite effect,promoting overactivation of the mPTP and promoting apoptosis.CONCLUSION MTCH2 can increase the malignant phenotype of GES-1 cells and promote the proliferation,invasion,and migration of gastric cancer cells by regulating mitochondrial function,providing a basis for targeted therapy for gastric cancer cells.

《Cell》:某些遗传性眼病中的视力丧失可能是由于肠道细菌进入眼睛引起

近日,一篇发表在《Cell》上的研究显示,该研究在小鼠中发现,某些遗传性眼病中的视力丧失可能是由肠道细菌引起的,而且可能可以通过抗菌剂治疗。CBR1(Crumbs homolog 1)基因在视网膜(位于眼球后部的一个较薄的细胞层)中表达,对于建立血液-视网膜屏障以调节哪些物质进出眼球至关重要。

Non-homologous functions of the AlkB homologs

TheDNArepair enzyme AlkB was identified in E.coli more than three decades ago.Since then,nine mammalian homologs,all members of the superfamily of alpha-ketoglutarate and Fe(II)-dependent dioxygenases,have been identified(designated ALKBH1–8 and FTO).While E.coli AlkB serves as a DNA repair enzyme,only two mammalian homologs have been confirmed to repair DNA in vivo.The other mammalian homologs have remarkably diverse substrate specificities and biological functions.Substrates recognized by the different AlkB homologs comprise erroneous methyl-and etheno adducts in DNA,unique wobble uridine modifications in certain tRNAs,methylated adenines in mRNA,and methylated lysines on proteins.The phenotypes of organisms lacking or overexpressing individual AlkB homologs include obesity,severe sensitivity to inflammation,infertility,growth retardation,and multiple malformations.Here we review the present knowledge of the mammalian AlkB homologs and their implications for human disease and development.

Relation between the equalized molecular chemical potential and the ionization potential of organic homologs

The ionization potential of organic homologs can be expressed as I_p=(∑X_i)/(a+bn).Here,X_i is the electronegativity(the average energy of valence electrons in a ground-state free atom)of the ith atomin an organic homologous molecule;n,the number of repeating units in the molecule;and(a+bn),the electronmoving range in the molecule orbit.The results of linear regression analysis show that the correlationcoefficients r are all "excellent"(r】0.990)for the 146 sets of photo electron spectroscopy data of 42 organichomologous series.

Association between homologous recombination deficiency and outcomes with platinum and platinum-free chemotherapy in patients with triple-negative breast cancer

Objective:The choice of chemotherapeutic regimen for triple-negative breast cancer(TNBC)remains controversial.Homologous recombination deficiency(HRD)has attracted increasing attention in informing chemotherapy treatment.This study was aimed at investigating the feasibility of HRD as a clinically actionable biomarker for platinum-containing and platinum-free therapy.Methods:Chinese patients with TNBC who received chemotherapy between May 1,2008 and March 31,2020 were retrospectively analyzed with a customized 3D-HRD panel.HRD positivity was defined by an HRD score≥30 or deleterious BRCA1/2 mutation.A total of 386 chemotherapy-treated patients with TNBC were screened from a surgical cohort(NCT01150513)and a metastatic cohort,and 189 patients with available clinical and tumor sequencing data were included.Results:In the entire cohort,49.2%(93/189)of patients were identified as HRD positive(40 with deleterious BRCA1/2 mutations and 53 with BRCA1/2 intact with an HRD score of≥30).In the first-line metastatic setting,platinum therapy was associated with longer median progression-free survival(mPFS)than platinum-free therapy[9.1 vs.3.0 months;hazard ratio(HR),0.43;95%confidence interval 0.22–0.84;P=0.01].Among HRD-positive patients,the mPFS was significantly longer in those treated with platinum rather than platinum-free therapy(13.6 vs.2.0 months;HR,0.11;P=0.001).Among patients administered a platinum-free regimen,HRD-negative patients showed a PFS significantly superior to that of HRD-positive patients(P=0.02;treatment-biomarker P-interaction=0.001).Similar results were observed in the BRCA1/2-intact subset.In the adjuvant setting,HRD-positive patients tended to benefit more from platinum chemotherapy than from platinum-free chemotherapy(P=0.05,P-interaction=0.02).Conclusions:HRD characterization may guide decision-making regarding the use of platinum treatment in patients with TNBC in both adjuvant and metastatic settings.

Oncogenic BRAF^(V600E) induces microglial proliferation through extracellular signal-regulated kinase and neuronal death through c-Jun N-terminal kinase

Activating V600E in v-Raf murine sarcoma viral oncogene homolog B(BRAF)is a common driver mutation in cancers of multiple tissue origins,including melanoma and glioma.BRAF^(V600E) has also been implicated in neurodegeneration.The present study aims to characterize BRAF^(V600E) during cell death and proliferation of three major cell types of the central nervous system:neurons,astrocytes,and microglia.Multiple primary cultures(primary cortical mixed culture)and cell lines of glial cells(BV2)and neurons(SH-SY5Y)were employed.BRAF^(V600E) and BRAF^(WT) expression was mediated by lentivirus or retrovirus.Blockage of downstream effectors(extracellular signal-regulated kinase 1/2 and JNK1/2)were achieved by siRNA.In astrocytes and microglia,BRAF^(V600E) induces cell proliferation,and the proliferative effect in microglia is mediated by activated extracellular signal-regulated kinase,but not c-Jun N-terminal kinase.Conditioned medium from BRAF^(V600E)-expressing microglia induced neuronal death.In neuronal cells,BRAF^(V600E) directly induces neuronal death,through c-Jun N-terminal kinase but not extracellular signal-regulated kinase.We further show that BRAF-related genes are enriched in pathways in patients with Parkinson’s disease.Our study identifies distinct consequences mediated by distinct downstream effectors in dividing glial cells and in neurons following the same BRAF mutational activation and a causal link between BRAF-activated microglia and neuronal cell death that does not require physical proximity.It provides insight into a possibly important role of BRAF in neurodegeneration as a result of either dysregulated BRAF in neurons or its impact on glial cells.

EZH2 Contributes to Anoikis Resistance and Promotes Epithelial Ovarian Cancer Peritoneal Metastasis by Regulating m6A

Objective:Histone modification has a significant effect on gene expression.Enhancer of zeste homolog 2(EZH2)contributes to the epigenetic silencing of target chromatin through its roles as a histone-lysine N-methyltransferase enzyme.The development of anoikis resistance in tumor cells is considered to be a critical step in the metastatic process of primary malignant tumors.The purpose of this study was to investigate the effect and mechanism of anoikis resistance in ovarian adenocarcinoma peritoneal metastasis.Methods:In addition to examining EZH2 protein expression in ovarian cancer omental metastatic tissues,we established a model of ovarian cancer cell anoikis and a xenograft tumor model in nude mice.Anoikis resistance and ovarian cancer progression were tested after EZH2 and N6-methyladenosine(m6A)levels were modified.Results:EZH2 expression was significantly higher in ovarian cancer omental metastatic tissues than in normal ovarian tissues.Reducing the level of EZH2 decreased the level of m6A and ovarian cancer cell anoikis resistance in vitro and inhibited ovarian cancer progression in vivo.M6a regulation altered the effect of EZH2 on anoikis resistance.Conclusion:Our results indicate that EZH2 contributes to anoikis resistance and promotes ovarian adenocarcinoma abdominal metastasis by m6A modification.Our findings imply the potential of the clinical application of m6A and EZH2 for patients with ovarian cancer.

miR-124 is upregulated in diabetic mice and inhibits proliferation and promotes apoptosis of high-glucose-inducedβ-cells by targeting EZH2

BACKGROUND Diabetes is a chronic metabolic disease,and a variety of miRNA are involved in the occurrence and development of diabetes.In clinical studies,miR-124 is highly expressed in the serum of patients with diabetes and in pancreatic isletβ-cells.However,few reports exist concerning the role and mechanism of action of miR-124 in diabetes.AIM To investigate the expression of miR-124 in diabetic mice and the potential mechanism of action in isletβ-cells.METHODS The expression levels of miR-124 and enhancer of zeste homolog 2(EZH2)in pancreatic tissues of diabetic mice were detected.The targeted relationship between miR-124 and EZH2 was predicted by Targetscan software and verified by a double luciferase reporter assay.Mouse isletβ-cells Min6 were grown in a high glucose(HG)medium to mimic a diabetes model.The insulin secretion,proliferation,cell cycle and apoptosis of HG-induced Min6 cells were detected after interference of miR-124a and/or EZH2.RESULTS The expression of miR-124 was upregulated and EZH2 was downregulated in the pancreatic tissue of diabetic mice compared with control mice,and the expression of miR-124 was negatively correlated with that of EZH2.miR-124 was highly expressed in HG-induced Min6 cells.Inhibition of miR-124 promoted insulin secretion and cell proliferation,induced the transition from the G0/G1 phase to the S phase of the cell cycle,and inhibited cell apoptosis in HG-induced Min6 cells.EZH2 was one of the targets of miR-124.Co-transfection of miR-124 inhibitor and siRNA-EZH2 could reverse the effects of the miR-124 inhibitor in HG-induced Min6 cells.CONCLUSION miR-124 is highly expressed in diabetic mice and HG-induced Min6 cells and regulates insulin secretion,proliferation and apoptosis of isletβ-cells by targeting EZH2.

Possible mechanisms associated with immune escape and apoptosis on anti-hepatocellular carcinoma effect of Mu Ji Fang granules

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most common digestive system cancers with high mortality rates worldwide.The main ingredients in Mu Ji Fang Granules(MJF)are alkaloids,flavonoids,and polysaccharides.MJF has been used in the clinical treatment of hepatitis,cirrhosis and HCC for more than 30 years.Few previous studies have focused on the mechanism of MJF on tumor immunology in the treatment of HCC.AIM To explore the mechanism of action of MJF on tumor immunology in the treatment of HCC.METHODS The absorbable ingredients of MJF were identified using Molecule Network related to High Performance Liquid Chromatography-Electron Spray Ionization-Time of Flight-Mass Spectrometry,and hub potential anti-HCC targets were screened using network pharmacology and pathway enrichment analysis.Forty male mice were randomly divided into the Blank,Model,and MJF groups(1.8,5.4,and 10.8 g/kg/d)following 7 d of oral administration.Average body weight gain,spleen and thymus indices were calculated,tumor tissues were stained with hematoxylin and eosin,and Interferon gamma(IFN-γ),Tumor necrosis factorα(TNF-α),Interleukin-2,aspartate aminotransferase,alanine aminotransferase,alpha-fetoprotein(AFP),Fas,and FasL were measured by Enzyme-linked Immunosorbent Assay.Relevant mRNA expression of Bax and Bcl2 was evaluated by Real Time Quantitative PCR(RTqPCR)and protein expression of Transforming growth factorβ1(TGF-β1)and Mothers against decapentaplegic homolog(SMAD)4 was assessed by Western blotting.The HepG2 cell line was treated with 10 mg/mL,20 mg/mL,30 mg/mL,40 mg/mL of MJF,and another 3 groups were treated with TGF-β1 inhibitor(LY364947)and different doses of MJF.Relevant mRNA expression of TNF-α,IFN-γ,Bax and Bcl2 was evaluated by RT-qPCR and protein expression of TGF-β1,SMAD2,p-SMAD2,SMAD4,and SMAD7 was assessed by Western blotting.RESULTS It was shown that MJF improved body weight gain and tumor inhibition rate in H22 tumorbearing mice,protected immune organs and liver function,reduced the HCC indicator AFP,affected immunity and apoptosis,and up-regulated the TGF-β1/SMAD signaling pathway,by increasing the relative expression of TGF-β1,SMAD2,p-SMAD2 and SMAD4 and decreasing SMAD7,reducing immune factors TNF-αand IFN-γ,decreasing apoptosis cytokines Fas,FasL and Bcl2/Bax,and inhibiting the effect of LY364947 in HepG2 cells.CONCLUSION MJF inhibits HCC by activating the TGF-β1/SMAD signaling pathway,and affecting immune and apoptotic cytokines,which may be due to MJF adjusting immune escape and apoptosis.

Axonal growth inhibitors and their receptors in spinal cord injury:from biology to clinical translation

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

Analyzing architectural diversity in maize plants using the skeletonimage-based method

Shoot architecture in maize is critical since it determines resource use,impacts wind and rain damage tolerance,and affects yield stability.Quantifying the diversity among inbred lines in heterosis breeding is essential,especially when describing germplasm resources.However,traditional geometric description methods oversimplify shoot architecture and ignore the plant’s overall architecture,making it difficult to reflect and illustrate diversity.This study presents a new method to describe maize shoot architecture and quantifies its diversity by combining computer vision algorithms and persistent homology.Our results reveal that persistent homology can capture key characteristics of shoot architecture in maize and other details often overlooked by traditional geometric analysis.Based on this method,the morphological diversity of shoot architecture can be mined(quantified),and the main shoot architecture types can be obtained.Consequently,this method can easily describe the diversity of shoot architecture in many maize materials.

COMPARISON OF HOMOLOGIES AND AUTOMATIC EXTENSIONS OF INVARIANT DISTRIBUTIONS

Let G be a reductive Nash group,acting on a Nash manifold X.Let Z be a G-stable closed Nash submanifold of X and denote by U the complement of Z in X.Letχbe a character of G and denote by g the complexified Lie algebra of G.We give a sufficient condition for the natural linear map H_(k)(g,S(U)×χ)→H_k(g,S(X)×χ)between the Lie algebra homologies of Schwartz functions to be an isomorphism.For k=0,by considering the dual,we obtain the automatic extensions of g-invariant(twisted by-χ)Schwartz distributions.

Promoter variations in DBR2-like affect artemisinin production in different chemotypes of Artemisia annua

Artemisia annua is the only known plant source of the potent antimalarial artemisinin,which occurs as the low-and high-artemisinin producing(LAP and HAP)chemotypes.Nevertheless,the different mechanisms of artemisinin producing between these two chemotypes were still not fully understood.Here,we performed a comprehensive analysis of genome resequencing,metabolome,and transcriptome data to systematically compare the difference in the LAP chemotype JL and HAP chemotype HAN.Metabolites analysis revealed that 72.18%of sesquiterpenes was highly accumulated in HAN compared to JL.Integrated omics analysis found a DBR2-Like(DBR2L)gene may be involved in artemisinin biosynthesis.DBR2L was highly homologous with DBR2,belonged to ORR3 family,and had the DBR2 activity of catalyzing artemisinic aldehyde to dihydroartemisinic aldehyde.Genome resequencing and promoter cloning revealed that complicated variations existed in DBR2L promoters among different varieties of A.annua and were clustered into three variation types.The promoter activity of diverse variant types showed obvious differences.Furthermore,the core region(-625 to 0)of the DBR2L promoter was identified and candidate transcription factors involved in DBR2L regulation were screened.Thus,the result indicates that DBR2L is another key enzyme involved in artemisinin biosynthesis.The promoter variation in DBR2L affects its expression level,and thereby may result in the different yield of artemisinin in varieties of A.annua.It provides a novel insight into the mechanism of artemisinin-producing difference in LAP and HAP chemotypes of A.annua,and will assist in a high yield of artemisinin in A.annua.

Antagonizing adipose tissue-derived exosome miR-103-hepatocyte phosphatase and tensin homolog pathway alleviates autophagy in non-alcoholic steatohepatitis:A trans-cellular crosstalk

BACKGROUND Obesity plays a vital role in the occurrence and development of non-alcoholic steatohepatitis(NASH).However,the underlining mechanism is still unclear,where adipose tissue(AT)derived exosomes may actively participate.MicroRNAs(miRNAs)are commonly secreted from exosomes for cell communication.Though the regulation of miR-103 on insulin sensitivity has been reported,the specific role of AT-derived exosomes miR-103 in NASH is still vague and further investigation may provide novel therapeutic choices.AIM To determine the specific role of AT-derived exosomes miR-103 in developing NASH through various methods.METHODS The expression levels of miR-103 in the AT-derived exosomes and livers were detected and compared between NASH mice and control.The effect of miR-103 on NASH progression was also explored by antagonizing miR-103,including steatosis and inflammation degree changes.The interaction between miR-103 and the autophagy-related gene phosphatase and tensin homolog(PTEN)was confirmed by dual-luciferase reporter assay.The role of the interaction between miR-103 and PTEN on autophagy was verified in NASH-like cells.Finally,the effects of miR-103 from adipose-derived exosomes on NASH and autophagy were analyzed through animal experiments.RESULTS The expression of miR-103 was increased in NASH mice,compared to the control,and inhibition of miR-103 could alleviate NASH.The results of the dual-luciferase reporter assay showed miR-103 could interact with PTEN.MiR-103-anta decreased p-AMPKa,p-mammalian target of rapamycin(mTOR),and p62 but increased the protein levels of PTEN and LC3-II/I and the number of autophagosomes in NASH mice.Similar results were also observed in NASH-like cells,and further experiments showed PTEN silencing inhibited the effect of miR-103-anta.AT derivedexosome miR-103 aggravated NASH and increased the expressions of p-AMPKa,p-mTOR,and p62 but decreased the protein levels of PTEN and LC3-II/I and the number of autophagosomes in mice.CONCLUSION AT derived-exosome increased the levels of miR-103 in the liver,and miR-103 aggravated NASH.Mechanically,miR-103 could interact with PTEN and inhibit autophagy.

Distributed Secure State Estimation of Multi-Agent Systems Under Homologous Sensor Attacks

This paper addresses the problem of distributed secure state estimation for multi-agent systems under homologous sensor attacks.Two types of secure Luenberger-like distributed observers are proposed to estimate the system state and attack signal simultaneously.Specifically,the proposed two observers are applicable to deal with the cases in the presence and absence of time delays during network communication.It is also shown that the proposed observers can ensure the attack estimations from different agents asymptotically converge to the same value.Sufficient conditions for guaranteeing the asymptotic convergence of the estimation errors are derived.Simulation examples are finally provided to demonstrate the effectiveness of the proposed results.

Phosphorylated S6K1 and 4E-BP1 play different roles in constitutively active Rheb-mediated retinal ganglion cell survival and axon regeneration after optic nerve injury

Ras homolog enriched in brain(Rheb) is a small GTPase that activates mammalian target of rapamycin complex 1(mTORC1).Previous studies have shown that constitutively active Rheb can enhance the regeneration of sensory axons after spinal cord injury by activating downstream effectors of mTOR.S6K1 and4E-BP1 are important downstream effectors of mTORC1.In this study,we investigated the role of Rheb/mTOR and its downstream effectors S6K1 and 4E-BP1in the protection of retinal ganglion cells.We transfected an optic nerve crush mouse model with adeno-associated viral 2-mediated constitutively active Rheb and observed the effects on retinal ganglion cell survival and axon regeneration.We found that overexpression of constitutively active Rheb promoted survival of retinal ganglion cells in the acute(14 days) and chronic(21 and 42 days) stages of injury.We also found that either co-expression of the dominant-negative S6K1mutant or the constitutively active 4E-BP1 mutant together with constitutively active Rheb markedly inhibited axon regeneration of retinal ganglion cells.This suggests that mTORC1-mediated S6K1 activation and 4E-BP1 inhibition were necessary components for constitutively active Rheb-induced axon regeneration.However,only S6K1 activation,but not 4E-BP1 knockdown,induced axon regeneration when applied alone.Furthermore,S6K1 activation promoted the survival of retinal ganglion cells at 14 days post-injury,whereas 4E-BP1 knockdown unexpectedly slightly decreased the survival of retinal ganglion cells at 14 days postinjury.Ove rexpression of constitutively active 4E-BP1 increased the survival of retinal ganglion cells at 14 days post-injury.Likewise,co-expressing constitutively active Rheb and constitutively active 4E-BP1 markedly increased the survival of retinal ganglion cells compared with overexpression of constitutively active Rheb alone at 14 days post-injury.These findings indicate that functional 4E-BP1 and S6K1 are neuroprotective and that 4E-BP1 may exert protective effects through a pathway at least partially independent of Rhe b/mTOR.Together,our results show that constitutively active Rheb promotes the survival of retinal ganglion cells and axon regeneration through modulating S6K1 and 4E-BP1 activity.Phosphorylated S6K1 and 4E-BP1 promote axon regeneration but play an antagonistic role in the survival of retinal ganglion cells.