Cell Life Cycle Research Articles

Pemodelan Farmakofor untuk Identifikasi Inhibitor Heat Shock Proteins-90 (HSP-90)

Heat shock proteins-90 (HSP-90) is a protein that plays an important role in the life cycle of normal and cancer cells for their self protection from thermal stress, oxidative damage, and cell hypoxia. Inhibition of HSP90 is one way to suppress the growth of cancer cells. In this study, pharmacophore modeling and molecular docking were conducted to identify hit compounds as inhibitors of HSP-90. The pharmacophore feature consists of three hydrogen bond acceptors, one hydrogen bond donor and one hydrophobic feature with Area Under Curve of Receiver Operating Characteristics (AUC-ROC) is 0.5 and the Goodness of Hit (GH) value is 0.752. Screening in the ZINC database generated 1,500 hit compounds, were subjected to molecular docking to determine their binding energy and interactions with HSP-90. The range of binding energy (E) of all hit compounds is -5.68 to -12.24 kcal/mol and there are four best hit compounds namely lig_543, lig_527, lig_1337 and lig_337, when compared to native ligands (PU2, E=-8.25 kkal/mol) based on the binding energy and orientation, which indicate their potential as new HSP-90 inhibitors.

Peptides targeting dengue viral nonstructural protein 1 inhibit dengue virus production

Viruses manipulate the life cycle in host cells via the use of viral properties and host machineries. Development of antiviral peptides against dengue virus (DENV) infection has previously been concentrated on blocking the actions of viral structural proteins and enzymes in virus entry and viral RNA processing in host cells. In this study, we proposed DENV NS1, which is a multifunctional non-structural protein indispensable for virus production, as a new target for inhibition of DENV infection by specific peptides. We performed biopanning assays using a phage-displayed peptide library and identified 11 different sequences of 12-mer peptides binding to DENV NS1. In silico analyses of peptide-protein interactions revealed 4 peptides most likely to bind to DENV NS1 at specific positions and their association was analysed by surface plasmon resonance. Treatment of Huh7 cells with these 4 peptides conjugated with N-terminal fluorescent tag and C-terminal cell penetrating tag at varying time-of-addition post-DENV infection could inhibit the production of DENV-2 in a time- and dose-dependent manner. The inhibitory effects of the peptides were also observed in other virus serotypes (DENV-1 and DENV-4), but not in DENV-3. These findings indicate the potential application of peptides targeting DENV NS1 as antiviral agents against DENV infection.

Generation of one iPSC line (IMEDEAi007-A) by Sendai Virus transduction of PBMCs from a Psoriasis donor.

Psoriasis is a chronic inflammatory skin disease that speeds up the life cycle of skin cells, forming scales and red patches that are itchy and sometimes painful. It is a complex disease of autoimmune origin and genetic predisposition with more than 10 different loci associated. Here we described the production of an iPSC line generated by Sendai Virus (Klf4, Oct3/4, Sox2 and c-Myc) reprogramming of Peripheral Blood Mononuclear Cells (PBMCs) from a Psoriasis patient. The iPSC line generated has normal 46XY karyotype, is free of SeV genome and transgenes insertions, express high levels of pluripotency markers and can differentiate into all three germ layers.

Complete microviscosity maps of living plant cells and tissues with a toolbox of targeting mechanoprobes

Mechanical patterns control a variety of biological processes in plants. The microviscosity of cellular structures effects the diffusion rate of molecules and organelles, thereby affecting processes such as metabolism and signaling. Spatial variations in local viscosity are also generated during fundamental events in the cell life cycle. While crucial to a complete understanding of plant mechanobiology, resolving subcellular microviscosity patterns in plants has remained an unsolved challenge. We present an imaging microviscosimetry toolbox of molecular rotors that yield complete microviscosity maps of cells and tissues, specifically targeting the cytosol, vacuole, plasma membrane, and wall of plant cells. These boron-dipyrromethene (BODIPY)-based molecular rotors are rigidochromic by means of coupling the rate of an intramolecular rotation, which depends on the mechanics of their direct surroundings, with their fluorescence lifetime. This enables the optical mapping of fluidity and porosity patterns in targeted cellular compartments. We show how apparent viscosity relates to cell function in the root, how the growth of cellular protrusions induces local tension, and how the cell wall is adapted to perform actuation surrounding leaf pores. These results pave the way to the noninvasive micromechanical mapping of complex tissues.

Graphene film with folds for a stable lithium metal anode

Lithium metal batteries (LMBs) are the most promising candidates for next-generation energy storage devices. However, uncontrollable dendrite growth limits the practical applications of LMBs. Herein, we report a graphene film with folds, which is applied between a Li metal anode and a separator as an interlayer, to regulate and inhibit dendrite growth and to simply create a Li anode capable of safe and stable circulation. Li metal anodes with graphene film can not only improve the life cycle of symmetrical cells up to 500 h at a low capacity of 1 mA h cm−2 and a low current density of 1 mA cm−2, but also promote cycle life up to 100 h at a capacity of 5 mA h cm−2 and a current density of 10 mA cm−2. In addition, we improve the electrochemical properties of lithium iron phosphate batteries and lithium-oxygen batteries by using a composite anode.

An ultra-high bandwidth nano-electronic interface to the interior of living cells with integrated fluorescence readout of metabolic activity

We present the first ever broadband, calibrated electrical connection to the inside of a cell. The interior of a vital, living cell contains multiple dynamic and electrically active organelles such as mitochondria, chloroplasts, lysosomes, and the endoplasmic reticulum. However, little is known about the detailed electrical activity inside the cell. Here we show an ultra-high bandwidth nano-electronic interface to the interior of living cells with integrated fluorescence readout of metabolic activity. On-chip/on-petri dish nanoscale capacitance calibration standards are used to quantify the electronic coupling from bench to cell from DC to 26 GHz (with cell images at 22 GHz). The interaction of static to high frequency electromagnetic fields with the cell constituents induce currents of free charges and local reorganization of linked charges. As such, this enables a direct, calibrated, quantitative, nanoscale electronic interface to the interior of living cells. The interface could have a variety of applications in interfacing life sciences to nano-electronics, including electronic assays of membrane potential dynamics, nano-electronic actuation of cellular activity, and tomographic, nano-radar imaging of the morphology of vital organelles in the cytoplasm, during all phases of the cell life cycle (from development to senescence), under a variety of physiological environments, and under a broad suite of pharmacological manipulations.

Critical Role of Type III Interferon in Controlling SARS-CoV-2 Infection in Human Intestinal Epithelial Cells

SummarySevere acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) is an unprecedented worldwide health problem that requires concerted and global approaches to stop the coronavirus 2019 (COVID-19) pandemic. Although SARS-CoV-2 primarily targets lung epithelium cells, there is growing evidence that the intestinal epithelium is also infected. Here, using both colon-derived cell lines and primary non-transformed colon organoids, we engage in the first comprehensive analysis of the SARS-CoV-2 life cycle in human intestinal epithelial cells (hIECs). Our results demonstrate that hIECs fully support SARS-CoV-2 infection, replication, and production of infectious de novo virus particles. We found that viral infection elicits an extremely robust intrinsic immune response where interferon-mediated responses are efficient at controlling SARS-CoV-2 replication and de novo virus production. Taken together, our data demonstrate that hIECs are a productive site of SARS-CoV-2 replication and suggest that the enteric phase of SARS-CoV-2 may participate in the pathologies observed in COVID-19 patients by contributing to increasing patient viremia and fueling an exacerbated cytokine response.

The dormant cancer cell life cycle.

The success of targeted therapies and immunotherapies has created optimism that cancers may be curable. However, not all patients respond, drug resistance is common and many patients relapse owing to dormant cancer cells. These rare and elusive cells can disseminate early and hide in specialized niches in distant organs before being reactivated to cause disease relapse after successful treatment of the primary tumour. Despite their importance, we are yet to leverage knowledge generated from experimental models and translate the potential of targeting dormant cancer cells to prevent disease relapse in the clinic. This is due, at least in part, to the lack of adherence to consensus definitions by researchers, limited models that faithfully recapitulate this stage of metastatic spread and an absence of interdisciplinary approaches. However, the application of new high-resolution, single-cell technologies is starting to revolutionize the field and transcend classical reductionist models of studying individual cell types or genes in isolation to provide a global view of the complex underlying cellular ecosystem and transcriptional landscape that controls dormancy. In this Perspective, we synthesize some of these recent advances to describe the hallmarks of cancer cell dormancy and how the dormant cancer cell life cycle offers opportunities to target not only the cancer but also its environment to achieve a durable cure for seemingly incurable cancers.

Abstract A17: Polyploid giant cancer cells lead to evolution of drug resistance in high-grade ovarian cancer

Abstract Whole genomic duplications (WGD) have been reported in 37% to 56% of high-grade cancers. WGD leads to formation of polyploid giant cancer cells (PGCCs) with salient and atypical nuclear morphology noted by light microscopy. However, PGCCs are generally considered nonviable due to their inability to execute mitosis. We have recently reported that PGCCs are capable of generating mitosis-competent progeny cells via primitive amitotic division including budding, splitting, and burst. We have further demonstrated that PGCCs are part of the process of somatic reprogramming named the giant cell life cycle composed of four distinct but overlapping phases including initiation, self-renewal, termination, and stability. The giant cell life cycle resets the somatic cell from the mitotic cycle to stress-induced endoreplication cell cycle via WGD to form PGCCs. The PGCCs activate endogenous embryonic factors for the reprogramming, which leads to the birth of drug-resistant cells by clonal selection from newly generated heterogeneous cancer stem cells. However, the underlying genetic and epigenetic mechanisms during WGD remain unclear. By mapping DNA methylation and whole-genome sequencing, monitoring the telomere dynamics, and tracking the cellular and nuclear morphology using microscopic time-lapse imaging observations during the time course of giant cell life cycle, we hereby provide new evidence that the daughters cells derived from PGCCs have massive alterations at the whole-genome and epigenome levels. The reprogrammed resistant daughter cells are achieved, at least in part, by genomic instability via shortened telomeres. Targeting PGCCs and promoting their differentiation during the course of giant cell life cycle may represent a novel approach to intercept drug resistance. Citation Format: Na Niu, Xiaoran Li, Jun Yao, Anil Sood, Jinsong Liu. Polyploid giant cancer cells lead to evolution of drug resistance in high-grade ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr A17.

Molecular plant responses to combined abiotic stresses put a spotlight on unknown and abundant genes.

Environmental stresses such as drought, heat, and salinity limit plant development and agricultural productivity. While individual stresses have been studied extensively, much less is known about the molecular interaction of responses to multiple stresses. To address this problem, we investigated molecular responses of Arabidopsis to single, double, and triple combinations of salt, osmotic, and heat stresses. A metabolite profiling analysis indicated the production of specific compatible solutes depending on the nature of the stress applied. We found that in combination with other stresses, heat has a dominant effect on global gene expression and metabolite level patterns. Treatments that include heat stress lead to strongly reduced transcription of genes coding for abundant photosynthetic proteins and proteins regulating the cell life cycle, while genes involved in protein degradation are up-regulated. Under combined stress conditions, the plants shifted their metabolism to a survival state characterized by low productivity. Our work provides molecular evidence for the dangers for plant productivity and future world food security posed by heat waves resulting from global warming. We highlight candidate genes, many of which are functionally uncharacterized, for engineering plant abiotic stress tolerance.

Antioxidant properties of plant polyphenols in the counteraction of alcohol-abuse induced damage: Impact on the Mediterranean diet

Polyphenols are antioxidants contained in plants as olive and grape. As part of the Mediterranean diet, they may decrease the risk of cancer, of chronic and neurodegenerative diseases. Alcohol consumption plays a detrimental effect on health, causing tissue damage and disrupting the metabolism of Neurotrophins (NTs). NTs are crucial proteins for the life cycle of neuronal and non-neuronal cells. Alcohol abuse elicits changes in NTs levels in the brain and in other target organs, however, it was observed minor damage in animals early exposed to red wine, probably due to the antioxidant effects of polyphenols. Indeed, data show that resveratrol or other polyphenols extracted from the olive can effectively counteract serum free radicals’ formation caused by chronic alcohol intake, contrasting also alcohol-induced NTs liver elevation. The aim of the present review is to update pieces of evidences about the antioxidant properties of polyphenols and their role in counteracting alcohol-induced damage.

Hypoxia factors suppression effect on the energy metabolism of a malignant melanoma cell SK-MEL-30.

Malignant melanoma (MM), as well as other cancers, is a disorder in the cell life cycle at many levels. In terms of energy, the sync of cytosolic and mitochondrial metabolism is required for each cell. Mismatches also caused by hypoxic factors accumulate defects leading to the formation, development and invasiveness of malignant melanoma. Our aim was to compare the effect of HIF-1α and miR-210 on the metabolism of malignant melanoma cells in normoxia and pseudohypoxia. Further, we also investigated how gene silencing affects the viability in order to evaluate the potential of gene therapy in the treatment of MM. We targeted oxidative phosphorylation by genetically suppressing HIF-1α and miR-210. We have examined mitochondrial activity, cytosolic glycolysis and cell viability. The ratio of NADH/NAD+ in the cytoplasm under normal conditions is stable and can thus serve as a specific cellular metabolic marker. Therefore, the study was aimed at finding the cause of the reduction in NADH levels in increasing hypoxia under ideal in vitro conditions on the SK-MEL-30 malignant melanoma cells. The relationship between HIF-1α and miR-210, their effect on transcriptional level, and the subsequent effect on metabolic process attenuation in cells was investigated. Obtained results indicate that the NADH which is accumulated by cells in hypoxia was significantly decreased upon gene silencing. Our studies have shown that small regulatory molecules with organelle-specific effect (such as miRs) need to be targeted, and that the resultant effect is comparable to silencing of "general" hypoxic transcription factors.

Metabolic analysis of tyrosine-kinase inhibitor effect on T cell activation

Abstract Tyrosine kinase inhibitors have been actively investigated as potential therapies for various cancers including blood tumors. However, as T cell activation can also be mediated by various tyrosine kinases, relevant inhibitors are also now being considered as pharmacological modulators of CAR-T cells; an example being dasatinib, which has been found to modulate CAR-T activity through Lck inhibition. T cell activation and subsequent differentiation are tightly associated with cellular metabolism, with T cells showing dynamic changes in two primary metabolic activities of glycolysis and mitochondrial respiration throughout the T cell life cycle. This metabolic response begins with an immediate early increase in glycolytic activity which has been shown to be an essential and signature response to activation. In this study, this fundamental biological process is exploited using the Agilent Seahorse XF technology, illustrating how activation can be measured in real-time in response to anti-CD3/CD28 activator injection, and further, how this parameter can be used to conveniently determine the modulatory effect of kinase inhibitors on T cell activation. Consistent with previous observations that kinase inhibitors can suppress naive T cell activation in vitro, here a similar kinase dependency in re-activation of resting (pre-activated) T cells was observed. Several kinase inhibitors also were able to downregulate the glycolytic rate elevated when applied post-activation. Taken together these data suggest that real-time metabolic analysis is a valuable tool in the characterization of putative T cell modulators, including tyrosine kinase inhibitors, and has the potential to inform the design of specific CAR-T modulators.

Wasp venom peptide as a new antichagasic agent

Chagas disease is caused by Trypanosoma cruzi and affects approximately 10 million people a year worldwide. The only two treatment options, benznidazole and nifurtimox, have low efficacy and high toxicity towards human cells. Mastoporan peptide (MP) a small cationic AMP from the venom of the wasp Polybia paulista has been reported as a potent trypanocidal agent. Thus, we evaluated the antichagasic effect of another AMP from the venom of the same wasp Polybia paulista, polybia-CP (ILGTILGLLSKL-NH2), and investigated its mechanism of action against different stages of the trypanosomal cells life cycle. Polybia-CP was tested against the epimastigote, trypomastigote and amastigote forms of the T. cruzi Y strain (benznidazole-resistant strain) and inhibited the development of these forms. We also assessed the selectivity of the AMP against mammalian cells by exposing LLC-MK2 cells to polybia-CP, the peptide presented a high selectivity index (>106). The mechanism of action of polybia-CP on trypanosomal cells was investigated by flow cytometry, scanning electron microscopy (SEM) and enzymatic assays with T. cruzi GAPDH (tcGAPDH), enzyme that catalyzes the sixth step of glycolysis. Polybia-CP induced phosphatidylserine exposure, it also increased the formation of reactive species of oxigen (ROS) and reduced the transmembrane mitochondrial potential. Polybia-CP also led to cell shrinkage, evidencing apoptotic cell death. We did not observe the inhibition of tcGAPDH or autophagy induction. Altogether, polybia-CP has shown the features of a promising template for the development of new antichagasic agents.

Novel Toscana Virus Reverse Genetics System Establishes NSs as an Antagonist of Type I Interferon Responses

The sand fly-borne Toscana virus (TOSV) is the major cause of human meningoencephalitis in the Mediterranean basin during the summer season. In this work, we have developed a T7 RNA polymerase-driven reverse genetics system to recover infectious particles of a lineage B strain of TOSV. The viral protein pattern and growth properties of the rescued virus (rTOSV) were found to be similar to those of the corresponding wild-type (wt) virus. Using this system, we genetically engineered a TOSV mutant lacking expression of the non-structural protein NSs (rTOSVɸNSs). Unlike rTOSV and the wt virus, rTOSVɸNSs was unable to (i) suppress interferon (IFN)-b messenger RNA induction; and (ii) grow efficiently in cells producing IFN-b. Together, our results highlight the importance of NSs for TOSV in evading the IFN response and provide a comprehensive toolbox to investigate the TOSV life cycle in mammalian and insect host cells, including several novel polyclonal antibodies.

Pathogenetic mechanisms of development of myocardial pathology in patients with malignant tumors: the current state of the problem

The myocardium, which has a high metabolic activity, responds to metabolic disorders and energy imbalance induced by a growing malignant tumor. In addition, the tumor itself can produce substances that directly affect metabolic processes and the life cycle of cells not involved in the neoplastic process, including cardiomyocytes. This review summarized and systematized current data on individual aspects of detrimental effects of oncogenes and tumor-related factors on the heart muscle and morpho-functional changes in the cardiovascular system of oncology patients. Also, the authors described in detail development of these pathogenetic mechanisms.

Protein arginine methyltransferase 5 promotes cholesterol biosynthesis-mediated Th17 responses and autoimmunity.

Protein arginine methyltransferase 5 (PRMT5) catalyzes symmetric dimethylation (SDM) of arginine, a posttranslational modification involved in oncogenesis and embryonic development. However, the role and mechanisms by which PRMT5 modulates Th cell polarization and autoimmune disease have not yet been elucidated. Here, we found that PRMT5 promoted SREBP1 SDM and the induction of cholesterol biosynthetic pathway enzymes that produce retinoid-related orphan receptor (ROR) agonists that activate RORγt. Specific loss of PRMT5 in the CD4+ Th cell compartment suppressed Th17 differentiation and protected mice from developing experimental autoimmune encephalomyelitis (EAE). We also found that PRMT5 controlled thymic and peripheral homeostasis in the CD4+ Th cell life cycle and invariant NK (iNK) T cell development and CD8+ T cell maintenance. This work demonstrates that PRMT5 expression in recently activated T cells is necessary for the cholesterol biosynthesis metabolic gene expression program that generates RORγt agonistic activity and promotes Th17 differentiation and EAE. These results point to Th PRMT5 and its downstream cholesterol biosynthesis pathway as promising therapeutic targets in Th17-mediated diseases.

The influence of bilateral environment of dyed-TiO2/electrolyte interface on detailed recombination process during the “mature” period of sensitized solar cell

The complete dye-sensitized solar cell (DSC) life cycle includes three stages: “mature” period, stability period and degradation period. However, during the DSC performance adjustment period, considering the influence of both sides of the dyed-TiO2/electrolyte interface on the electron recombination process is still blank. In this paper, the effects of the environment on both sides of the interface between TiO2 and electrolyte during the DSC performance adjustment on the electron recombination process are studied. The results show that the performance adjustment of DSC is greatly influenced by the chemical environment of electrolyte. The film microstructures have a certain influence on the electron recombination process during the performance adjustment. During the performance adjustment period of DSC, the adjustment of quasi-Fermi level is more complicated under the condition of weak light than under the condition of strong light. The results of this paper are significant for studying complex systems of DSC, understanding the device working mechanism and improving the cell efficiency.

Histone-fold centromere protein W (CENP-W) is associated with the biological behavior of hepatocellular carcinoma cells

ABSTRACT Centromere protein W (CENP-W), identified as a centromeric component, plays an important role in the cell life cycle. However, how CENPW expression affects biological processes in liver cancer cells remains unknown. In this article, we found that CENPW was overexpressed in liver cancer tissues. Low CENPW expression was correlated with a better prognosis in hepatocellular carcinoma (HCC) patients, compared to high CENPW expression. The results of qRT-PCR and western blot assay showed that CENPW was effectively knocked down in HCC cells using siRNA transfection. Cell proliferation, migration, and invasion were inhibited. Cell apoptosis rates were increased. The cells were arrested in the G2/M phase of the cell cycle. Subsequently, 127 differentially expressed genes (DEGs) were identified based on RNA-seq data. GO and KEGG enrichment and PPI network analysis were performed. The novel DEGs were found and mainly enriched in nucleosome assembly and the complement system. In summary, our study indicated that overexpression of CENPW implied unfavorable prognosis and CENPW might be the potential predictive biomarker in liver cancer. Downregulation of CENPW might inhibit the HCC developmentby regulating the expression of the molecules in nucleosomes and the complement system.

The Fundamentals of miRNA Biology: Structure, Biogenesis, and Regulatory Functions

Epigenetic regulation of gene expression plays a key role in controlling many cellular processes. One essential element of such regulation are miRNAs—a class of short non-coding RNAs. The miRNAs were first discovered in 1993, but their active investigation was not started until early 2000s. Recent data show that miRNAs regulate the expression of at least half of human genes. Being involved in regulation of numerous target genes implicated in cell functioning, miRNA activity is critical for normal human development and function, while dysregulation of miRNA is a hallmark of various pathophysiological processes. Current review introduces the reader to the main stages of miRNA life cycle in human cells. The origins of cellular miRNAs, their biogenesis, functions, and regulation of their activity are discussed. The publication is aimed at readers looking for first insights into the intricacies of miRNA biology, but can also serve as a source of reference material for specialists in the area.