Effects of H pylori infection on gap-junctional intercellular communication and proliferation of gastric epithelial cells in vitro

AIM： To explore the effects of H pylori infection on gap-junctional intercellular communication （GJIC） and proliferation of gastric epithelial cells in vitro. METHODS： A human gastric epithelial cell line （SGC- 7901） cultured on coverslips was exposed overnight to intact H pylori （CagA^＋ or CagA^- strains） and sonicated extracts, respectively. GJIC between the cells was detected by fluorescence redistribution after photobleaching （FRAP） technique. Proliferation of SGC cells was determined by methylthiazolyl tetrazolium （MTT） assay. RESULTS： When compared with control in which cells were cultured with simple medium alone, both CagA^＋ and CagA^- H pylori isolates could inhibit GJIC （CagA^＋： F = 57.98, P 〈 0.01; CagA^-： F = 29.59, P 〈 0.01） and proliferation （CagA^＋： F = 42.65, P 〈 0.01; CagA^-： F = 58.14, P 〈 0.01） of SGC-7901 cells. Compared with CagA^- strains, CagA^＋ H pylori more significantly downregulated GJIC of gastric cells （intact Hpylori： t = 13.86, P 〈 0.01; sonicated extracts： t = 11.87, P 〈 0.01） and inhibited proliferation gastric cells to a lesser extent in vitro （intact H pylori： t = 3.06, P 〈 0.05; sonicated extracts： t = 3.94, P 〈 0.01）. CONCLUSION： Compared with CagA^- H pylori strains, CagA^＋ strains down-regulate GJIC of gastric epithelial cells more significantly and inhibit proliferation of gastric cells to a lesser extent in vitro. H pylori, especially CagA^＋ strains, may play an important role in gastric carcinogenesis.

Altered Expression of Connexin-43 and Impaired Capacity of Gap Junctional Intercellular Communication in Prostate Cancer Cells

Connexin-43 (Cx43) expression in prostate cancer (PCa) cells and the potency of gap junctional intercellular communication (GJIC) in the cells were investigated, with an attempt to elu- cidate the reason why the so-called 'bystander effect' mediated by thymidine kinase (TK) suicide gene therapy on PCa cells is not of significance and to explore the role of GJIC in PCa carcinogenesis. mRNA and protein expression of Cx43 in a PCa cell line PC-3m was detected by re- verse-transcription polymerase chain reaction (RT-PCR) and strapt-avidin-biotin-enzyme complex (SABC) immunohistochemical staining, and inherent GJIC of PC-3m cells was assayed by scrape-loading and dye transfer (SLDT) assay. The expression of Cx43 in human normal and malig- nant prostate tissues was determined by SABC immunohistochemistry as well. It was found that Cx43 mRNA and protein expression in PC-3m cells was slightly reduced as compared with positive controls and the location of Cx43 protein was aberrant in cytoplasm rather than on membrane. As- sessment of paraffin sections demonstrated that the expression of Cx43 protein in PCa cells was ab- normally located and markedly diminished as compared with normal prostatic epithelial ones, dis- playing a negative correlation to the pathological grade (χ2=4.025, P<0.05). Additionally, capacity of inherent GJIC in PC-3m cells was disrupted, which was semi-quantified as (+) or (-). It was indi- cated that both down-regulated expression of Cx43 mRNA and aberrant location of Cx43 protein par- ticipated in the mechanisms leading to deficient GJIC in PC-3m cells. Lack of efficient GJIC is a molecular event, which may contribute not only to limited extent of 'bystander effect', but also to initiation and progression of prostatic neoplasm.

Exosomes rewire the cartilage microenvironment in osteoarthritis:from intercellular communication to therapeutic strategies

Osteoarthritis(OA)is a prevalent degenerative joint disease characterized by cartilage loss and accounts for a major source of pain and disability worldwide.However,effective strategies for cartilage repair are lacking,and patients with advanced OA usually need joint replacement.Better comprehending OA pathogenesis may lead to transformative therapeutics.Recently studies have reported that exosomes act as a new means of cell-to-cell communication by delivering multiple bioactive molecules to create a particular microenvironment that tunes cartilage behavior.Specifically,exosome cargos,such as noncoding RNAs(ncRNAs)and proteins,play a crucial role in OA progression by regulating the proliferation,apoptosis,autophagy,and inflammatory response of joint cells,rendering them promising candidates for OA monitoring and treatment.This review systematically summarizes the current insight regarding the biogenesis and function of exosomes and their potential as therapeutic tools targeting cell-to-cell communication in OA,suggesting new realms to improve OA management.

Intercellular communication of notochord cells during their differentiation in Cynops orientalis

Intercellular communication of notochord cells during their differentiation was studied by microinjection of a fluorescent dye, Lucifer Yellow. Close correlation existed between the incidences of dye coupling and quantitative evaluation of gap junctions. High incidences of dye coupling and of gap junctions occurred at a stage when notochord cells were active in the change of cell shape and cell arrangement. With the subsidence of cell movements, both dye coupling and gap junctions were reduced to lower levels. It was, therefore, suggested that intercellular communication via gap junctions played an important role in the coordination of notochord cell movements.Gap junctions of altered configuration occurred in notochord cells in late tailbud stage. The comparison of incidences of dye coupling at this stage with those at other stages strongly suggested that the gap junctions of altered configuration functioned just as those of generalized type.

Changes of gap junctional intercellular communication in detrusor instability

Objective: To demonstrate the functional changes of gap junctional mediation of intercellular communication in detrusor instability (DI) and its mechanisms. Methods: The function of gap junctional intercellular communication in the cultured bladder detrusor cells was detected by fluorescence redistribution after photobleaching. Results: At the fourth minute after bleaching, the mean fluorescences recovery rates of DI group bladder detrusor cells were (35 791±0 836)%, that of control group (8 645±0 673)%. The mean fluorescence recovery rates of DI group were significantly higher than those of control group ( P <0 01). Conclusion: It shows that the increase of intercellular excitatory communication is one of the important reasons of pathogenesis of DI.

Influence of (-)-epigallocatechin-3-gallate on the expression of connexin43 and gap junction intercellular communication of the bladder cancer cell lines BIU-87 in vitro

Objective： The aim of our study was to investigate the effects of （-）-epigallocatechin-3-gallate （EGCG, the major phytochemistry component in green tea） on the expression of connexin43 （Cx43） gene and detect the intercellular communication of the human bladder cancer cell lines BIU-87, and explore its possible mechanisms of prevention and cure for the bladder tumor. Methods： The methyl thiazolyl tetrazolium and Annexin-V/PI double-labeled flow cytometry methods were used to observe the growth inhibitory rate （IR） and apoptosis rate （AR） of BlU-87 cells treated by EGCG at different concentrations （0, 5, 10 and 20 mg/L）, respectively. The reverse transcription-polymerase chain reaction （RT-PCR） and Western Blotting analysis were employed to detect the relative expression levels of the Cx43 mRNA and its protein. The scrape-loading fluorescence dye transfer method was used to assess the gap junction intercellular communication （GJIC） under fluorescence microscope. Results： EGCG at concentrations （10 and 20 mg/L） both could significantly inhibit the proliferation and induce the apoptosis of BIU-87 cells. The IR and AR were （15.67 ± 1.15）%, （18.33 ± 1.53）% and （42.00 ± 4.34）%, （27.33 ± 3.21）%, respectively. And compared with the control groups of 0 mg/L and 5 mg/L （P 〈 0.05）, EGCG could significantly up-regulate the expression of Cx43 mRNA and its protein and enhance the function of BIU-87 cells. The effects had the significant correlation with the dose-dependent of EGCG. Conclusion： EGCG （10, 20 mg/L） could effectively up-regulate Cx43 expression and enhance the GJIC of BlU-87 cells. The results may indicate the effects of EGCG inducing bladder tumor cells apoptosis and inhibiting its growth which provides the experimental evidence for further demonstrating the mechanism of chemical prevention and cure for the bladder tumor by EGCG.

Connexin 43-modified bone marrow stromal cells reverse the imatinib resistance of K562 cells via Ca^(2+)-dependent gap junction intercellular communication

Background: Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown. Methods: Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca^(2+)-related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance. Results: Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca ^(2+ )is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments. Conclusions: Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.

Single-cell profiling reveals Müller glia coordinate retinal intercellular communication during light/dark adaptation via thyroid hormone signaling

Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination.Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation.However,various types of neurons and glial cells exist in the retina,and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation.Therefore,we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice.The results demonstrated that,in addition to photoreceptors,other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation.Importantly,Müller glial cells(MGs)were identified as hub cells for intercellular interactions,displaying complex cell‒cell communication with other retinal cells.Furthermore,light increased the transcription of the deiodinase Dio2 in MGs,which converted thyroxine(T4)to active triiodothyronine(T3).Subsequently,light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions.As cones specifically express the thyroid hormone receptor Thrb,they responded to the increase in T3 by adjusting light responsiveness.Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones.These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.

Identification of immune feature genes and intercellular profiles in diabetic cardiomyopathy

BACKGROUND Diabetic cardiomyopathy(DCM)is a multifaceted cardiovascular disorder in which immune dysregulation plays a pivotal role.The immunological molecular mechanisms underlying DCM are poorly understood.AIM To examine the immunological molecular mechanisms of DCM and construct diagnostic and prognostic models of DCM based on immune feature genes(IFGs).METHODS Weighted gene co-expression network analysis along with machine learning methods were employed to pinpoint IFGs within bulk RNA sequencing(RNA-seq)datasets.Single-sample gene set enrichment analysis(ssGSEA)facilitated the analysis of immune cell infiltration.Diagnostic and prognostic models for these IFGs were developed and assessed in a validation cohort.Gene expression in the DCM cell model was confirmed through real time-quantitative polymerase chain reaction and western blotting techniques.Additionally,single-cell RNA-seq data provided deeper insights into cellular profiles and interactions.RESULTS The overlap between 69 differentially expressed genes in the DCM-associated module and 2483 immune genes yielded 7 differentially expressed immune-related genes.Four IFGs showed good diagnostic and prognostic values in the validation cohort:Proenkephalin(Penk)and retinol binding protein 7(Rbp7),which were highly expressed,and glucagon receptor and inhibin subunit alpha,which were expressed at low levels in DCM patients(all area under the curves>0.9).SsGSEA revealed that IFG-related immune cell infiltration primarily involved type 2 T helper cells.High expression of Penk(P<0.0001)and Rbp7(P=0.001)was detected in cardiomyocytes and interstitial cells and further confirmed in a DCM cell model in vitro.Intercellular events and communication analysis revealed abnormal cellular phenotype transformation and signaling communication in DCM,especially between mesenchymal cells and macrophages.CONCLUSION The present study identified Penk and Rbp7 as potential DCM biomarkers,and aberrant mesenchymal-immune cell phenotype communication may be an important aspect of DCM pathogenesis.

THE EFFECT OF ALL-TRANS RETINOIC ACID ON GAP JUNCTIONAL INTERCELLULARCOMMUNICATION AND CONNEXIN 43 GENE EXPRESSION IN GLIOMA CELLS

To illuminate the regulating effect of all trans retinoic acid (ATRA ) on gap junctional intercellular communication (GJIC) and connexin 43 (Cx43) ge ne expression in glioma cells, which is tissue and organ specific. Method. Rat C6 glioma cells were exposed to ATRA at a concentration of 1, 10, 10 0 μmol/L respectively, and the GJIC function of the cells was examined with scr ape loading dye transfer assay 24 hours, 48 hours and 72 hours after ATRA treat ment. The effect of ATRA on Cx43 gene expression was measured with semiquantitat ive reverse transcription polymerase chain reaction (RT PCR) 24 hours after ATR A exposure. Results. The GJIC function of C6 glioma cells was significantly increased by ATR A at each concentration applied. The dye passed 4 to 5 rows of cells from the sc raping edge in ATRA treated cells, but only 1 or 2 rows in the control. The augm ent effect was observed 24 hours after each concentration ATRA treatment, and la sted till 72 hours after treatment with 1μmol/L and 10μmol/L ATRA. Forty eigh t hours after exposed to 100μmol/L ATRA, the enhancement of GJIC was less obvi ous. There was no significant increase induced by ATRA on the transcription of C x43 gene, as demonstrated by semiquantitative RT PCR. Conclusion. ATRA turned out to be a potent enhancer on GJIC function in C6 gliom a cells, and the enhancement effect was most probable at post transcriptional l evel.

EFFECTS OF LIMONENE,SALVIA MILTIORRHIZA AND TURMERIC DERIVATIVES ON H-RAS ONCOGENE EXPRESSION AND GAP JUNCTION INTERCELLULAR COMMUNICATION IN HUMAN SOLID TUMOR CELL LINES

Objective: To study gap junction intercellular communication (GJIC), H ras oncogene expression and ras oncogene product (P 21 ras protein) expression in four human solid tumor cell lines, W1-38,CACO 2,A549 and PaCa, and the effects of four compounds, Salvia miltiorrhiza derivative (SMD), d Limonene, Turmeric derivative I (TD I) and Turmeric derivative II (TD II), on them. Methods: The abilities of the four solid tumor cell lines to transfer dye to adjacent cells were examined by the scrape loading/dye transfer technique, and the H ras oncogene expression by Northern blotting and P 21 ras protein expression by Western blotting. Results: The results showed the loss of intercellular coupling in PaCa cells, slight GJIC in A549 and CACO 2 cells, and a good GJIC in W1-38 cells. The four compounds could improve the GJIC of PaCa to different extents. The amount of total and membrane associated P 21 ras in PaCa cells were decreased after treatment with SMD, d Limonene and TD I (2.5 μg/ml) for 48 h. Concomitantly, the growth of PaCa cells decreased in soft agar and had enhanced GJIC. The relative potency was found to be:d Limonene>SMD >TD I=TD II. There was no significant effect of the four compounds on H ras oncogene expression. Conclusion: It was suggested that there was an excellent correlation between loss of Lucifer Yellow dye transfer and ras gene mutation rate in the four solid tumor cell lines (ras gene mutation rate inversely correlated with average cell number coupled, r=0.98) i.e., the high ras gene mutation was closely correlated with loss of GJIC in these malignant human tumor cells; The antitumor effect of the monoterpene d Limonene and the phenol compound, SMD, might be related to inhibition of P 21 ras membrane association and enhancement of GJIC, whilst that of the others may be by a different mechanism; The inhibition of P 21 ras membrane association was directly related to the enhancement of gap junction intercellular com munication.

STUDIES ON THE GAP JUNCTIONAL INTERCELLULARCOMMUNICATION OF HUMAN NASOPHARYNGEALCARCINOMA CELLS AND THE EFFECT OF RII

Human nasopharyngeal carcinoma(NPC) cell line,CNE-2Z, and its clones(L2, H2, L4) with various invasive and metastatic potentials were examined for their gap junctions(GJ), gap junctional intercellular communication(GJIC) and the concentration of cytosolic free calcium(Ca2+). Only a few intermediate junction(IJ)but no GJ structures were observed under electron microscope(EM). CNE-2Z cells showed marked JGIC,while its variants lacked this function using the scraploading dye-transfer technique(SLDT). There was lower concentration of[Ca2+]. in L2 cells(a variant with high invasive and metastatic Potential) compared to that in H2 and L4 cells(variants with medium and low invasive and metastatic Potentials, respectively). These data suggested that high invasive and metastatic potentials might be correlated with the levcl of[Ca2+]i in NPC cells.The effect of RII(4-hydroxycarbophenyl retinamide) on NPC cells also investigated, After 3-7 d of RII(10-5 M) treatment, there was no change in the number of gap junctions and other kind of intercellular junctions in NPC cells observed under EM. The JGIC of CNE-2Z weaked and then disappeared finally with prolonging of RII treatment. However. there was no influence on its variants. The level of[Ca2+], in NPC cells apparently fell after 6 h of RII treatment, and rose to original level with persisting of RII treatment. Whether the fluctuating of[Ca2+]i level is related to the inhibitory effect of RII treatment on growth and invasion of NPC cells needs to be further studied.

Single-cell manipulation by two-dimensional micropatterning

Cells are highly sensitive to their geometrical and mechanical microenvironment that directly regulate cell shape,cytoskeleton and organelle,as well as the nucleus morphology and genetic expression.The emerging two-dimensional micropatterning techniques offer powerful tools to construct controllable and well-organized microenvironment for single-cell level investigations with qualitative analysis,cellular standardization,and in vivo environment mimicking.Here,we provide an overview of the basic principle and characteristics of the two most widely-used micropatterning techniques,including photolithographic micropatterning and soft lithography micropatterning.Moreover,we summarize the application of micropatterning technique in controlling cytoskeleton,cell migration,nucleus and gene expression,as well as intercellular communication.

Fas stimulation of T lymphocytes promotes rapid intercellular exchange of death signals via membrane nanotubes

The Fas/CD95 surface receptor mediates rapid death of various cell types, including autoreactive T cells with the potential for triggering autoimmunity. Here, we present novel aspects of Fas signalling that define a ＇social＇ dimension to receptor-induced apoptosis. Fas stimulation rapidly induces extensive membrane nanotube formation between neighbouring T cells. This is critically dependent on Rho GTPases but not on caspase activation. Bidirectional transfer of membrane and cytosolic elements including active caspases can be observed to occur via these nanotubes. Nanotube formation and intercellular exchanges of death signals are defective in T lymphocytes from patients with autoimmune iymphoproliferative syndrome harbouring mutations in the Fas receptor. We conclude that nanotuhemediated exchanges constitute a novel form of intercellular communication that augments the propagation of death signalling between neighbouring T cells.

Single-cell analysis of cellular heterogeneity and interactions in the ischemia-reperfusion injured mouse intestine

Nine major cell populations among 46,716 cells were identified in mouse intestinal ischemia‒reperfusion(II/R)injury by single-cell RNA sequencing.For enterocyte cells,11 subclusters were found,in which enterocyte cluster 1(EC1),enterocyte cluster 3(EC3),and enterocyte cluster 8(EC8)were newly discovered cells in ischemia 45 min/reperfusion 720 min(I 45 min/R 720 min)group.EC1 and EC3 played roles in digestion and absorption,and EC8 played a role in cell junctions.For TA cells,after ischemia 45 min/reperfusion 90 min(I 45 min/R 90 min),many TA cells at the stage of proliferation were identified.For Paneth cells,Paneth cluster 3 was observed in the resting state of normal jejunum.After I 45 min/R 90 min,three new subsets were found,in which Paneth cluster 1 had good antigen presentation activity.The main functions of goblet cells were to synthesize and secrete mucus,and a novel subcluster(goblet cluster 5)with highly proliferative ability was discovered in I 45 min/R 90 min group.As a major part of immune system,the changes in T cells with important roles were clarified.Notably,enterocyte cells secreted Guca2b to interact with Gucy2c receptor on the membranes of stem cells,TA cells,Paneth cells,and goblet cells to elicit intercellular communication.One marker known as glutathione S-transferase mu 3(GSTM3)affected intestinal mucosal barrier function by adjusting mitogen-activated protein kinases(MAPK)signaling during II/R injury.The data on the heterogeneity of intestinal cells,cellular communication and the mechanism of GSTM3 provide a cellular basis for treating II/R injury.

Cisplatin-induced premature senescence with concomitant reduction of gap junctions in human fibroblasts

To examine the role of gap junctions in cell senescence,the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent human fibroblasts.Dye transfer assay for gap junction function and immunofluorescent staining for connexin 43 protein distribution were done respectively. Furthermore,cytofluorimetry and DAPI fluorescence staining were performed for cell cycle and apoptosis analysis. p53 gene expression level was detected with indirect immunofluorescence. We found that cisplatin (10 mM) treatment could block cell growth cycle at G1 and induced premature senescence. The premature senescence changes included high frequency of apoptosis,elevation of p53 expression,loss of membranous gap junctions and reduction of dye-transfer capacity. These changes were comparable to the changes of replicative senescence of human fibroblasts. It was also concluded that cisplatin could induce premature senescence concomitant with inhibition of gap junctions in the fibroblasts. Loss of functional gap junctions from the cell membrane may account for the reduced intercellular communication in the premature senescent fibroblasts. The cell system we used may provide a model useful for the study of the gap junction thus promoting agents against premature senescence.

Genotoxic and Nongenotoxic Effects of Glycidyl Methacrylate on Human Lung Fibroblast Cells

Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.

Energy intake,metabolic homeostasis,and human health

The energy substances(mainly carbohydrates and fats)are the basis and guarantee of life activity,especially the oxidative phosphorylation for energy supply.However,excessive absorption and accumulation of these substances can lead to metabolic diseases such as obesity,hyperlipidemia,diabetes,and cancers.A large amount of studies demonstrate that G protein-coupled receptors(GPCRs)play a key role in identification and absorption of energy substances,and the signaling network of nerves,immune,and endocrine regulates their storage and utilization.The gastrointestinal mucus layer not only identifies these substances through identification in diet components but also transfers immune,metabolic,and endocrine signals of hormones,cytokines,and chemokines by promoting interactions between receptors and ligands.These signaling molecules are transferred to corresponding organs,tissues,and cells by the circulatory system,and cell activity is regulated by amplifying of cell signals that constitute the wireless communication network among cells in the body.Absorption,accumulation,and utilization of energy substances in the body obey the law of energy conservation.Energy is stored in the form of fat,and meets the demand of body via two coupled mechanisms:catabolism and oxidative phosphorylation.Under normal physiological conditions,fat consumption involves ketone body metabolism through the circulatory system and glucose consumption requires blood lactic acid cycle.Accumulation of excessive energy leads to the abnormal activation of mammalian target of rapamycin(mTOR),thus promoting the excretion of glucose or glycogen in the form of blood glucose and urine glucose.Alternatively,the body cancels the intercellular contact inhibition and promotes cell proliferation to induce carcinogenesis,which can induce the consumption of large amounts of glucose.Intercellular communication is performed by signaling molecules via sensing,absorption,accumulation,and utilization of energy substances,and anabolism and catabolism are controlled by the central metabolic pathway.Therefore,slower catabolism will result in longer life expectancy,whereas faster catabolism results in shorter life expectancy.Energy substances in diet influence the balance between energy and metabolism in the body through the sensing function of the gastrointestinal system at two levels:cellular communication network and metabolic network.The present review of studies aims to strengthen our knowledge on cellular communication and metabolic networks to offer a dietary guidance on the metabolism and communication role of various foods.

Connexin 40-formed GJIC increases the phototoxicity of photodynamic therapy through ROS-and calcium-mediated pathways

OBJECTIVE To explore the effect of connexin(Cx)40-formed gap junctional intercellular communication(GJIC)on Photofrin-photodynamic therapy(PDT)phototoxicity in Cx40-transfected He La cells and its potential mechanisms.METHODS He La cell line stably transfected to express Cx40 was seeded at high and low cell density,respectively,to assess in vitro photosensitivity using CCK8 assay.Western blot assay was performed to detect the expression of Cx40.The intracellular ROS and Ca^(2+) concentrations were determined using flow cytometer.4-HNE and ceramide were measured using ELISA assay.RESULTS Cx40-composed GJ formation at high density enhances the phototoxicity of PhotofrinPDT.When the Cx40 is not expressed or Cx40 channels are blocked,the phototoxicity in high-density cultures substantially reduces,indicating that the enhanced PDT phototoxicity at high density is mediated by Cx40-composed GJIC.The GJIC-mediated increase in PDT phototoxicity was associated with ROS and calcium-mediated stress signaling pathways.CONCLUSION The work uniquely presents the ability of Cx40-composed GJIC to enhance the sensitivity of malignant cells to PDT,and indicates that maintenance or increase of Cx40-formed GJIC may be a profitable strategy towards the enhancement of PDT therapeutic efficiency.

The effect of exosomes in transferring TET signaling alterations

Ten eleven translocation(TET)enzymes are composed of three representatives:TET1/2/3 which are involved in the hydroxymethylation of methylated cytosines.Because of the wide array of processes that are governed by these epigenetic marks,there have been a wide range of clinical effects associated with TET alterations.Even though many research groups have focused on analyzing the effect of TET alterations within certain cells,few have taken into consideration the effect of TET in the context of intercellular communication.One important entity through which intercellular communication occurs is represented by exosomes.Thus,in the current viewpoint we discussed the direct transfer of TET by exosomes,its alterations in the cell targeted by exosomes and the effect of TET alterations on exosome secretion.