Traditional Chinese medicine formula T33 inhibits the proliferation of human colorectal cancer cells by inducing autophagy.

Colorectal cancer (CRC) is a leading cause of cancer-related death globally. Although surgery is still the major method for CRC therapy, the adoption of alternative treatments, such as traditional Chinese medicine (TCM), for CRC treatment is increasing. Our previous study has indicated the anti-breast cancer activity of T33 (a TCM formula). Interestingly, a major ingredient in T33, Baishao (Paeoniae Radix Alba), was reported to have antiproliferative effects on CRC cells. Therefore, this study further validated the influences of T33 on HT-29 and Caco2 cells both in vitro and in vivo. Viability and migration assays were performed to analyze the influences of T33 on proliferation and migratory activity of HT-29 and Caco2 cells. Immunofluorescence (IF) staining and immunoblotting were performed to confirm T33-induced autophagy in HT-29 and Caco2 cells. Xenograft HT-29 tumors were generated to test the effects of T33 in vivo. Significantly reduced survival and migratory activity were observed in both HT-29 and Caco2 cells treated with T33 along with apparently increased LC3-II protein. Significantly decreased p62/SQSTM1 protein, increased LC3-II/LC3-I ratio, and elevated amounts of Atg7, Atg5, and Beclin-1 proteins were detected in both HT-29 and Caco2 cells treated with T33. Moreover, the volume of xenograft HT-29 tumors was significantly lower in mice receiving 200 or 600 mg/kg T33 than in control-treated mice. These findings indicate that T33 exerts anti-CRC activity by inducing autophagy and suggest the potential of T33 for CRC treatment.

Experience of patients with COVID-19 in hospital isolation in Taiwan.

The COVID-19 pandemic has significantly impacted everyone's lives, challenging us in ways that can be frustrating, daunting, and intensely emotive. This qualitative study explored the isolation experiences of patients with COVID-19 in a hospital in northern Taiwan. We collected data from nine patients in June-July 2020, conducting semi-structured, virtual face-to-face, in-depth interviews to gather input on two topics: (1) the psychological effect of hospital isolation on patients, including the psychological burden, stress response, support, disease stigma, and fear of returning to society; and (2) the patients' cognition and behaviors, which included tracking epidemic information, monitoring disease progression, soliciting suggestions about hospital isolation, and gauging comprehension after recovery. The results confirmed that hospital isolation significantly impacts patients physically, psychologically, spiritually, and socially. Thus, the isolated patients faced the dual challenges of fighting, adapting to, and recovering from the disease itself and struggling in isolation to maintain positive beliefs, independently assess their condition, and gain strength from the knowledge of continuing social support.

Association of auditory hallucination and anxiety symptoms with depressive symptoms in patients with schizophrenia: A three-month follow-up.

This study was to investigate the association of auditory hallucinations and anxiety symptoms with depressive symptoms in patients with schizophrenia for three months. The participants (N = 189) were evaluated using Characteristics of Auditory Hallucination Questionnaire (CAHQ), Beck Anxiety Inventory (BAI), and Beck Depression Inventory-II. Forty-two participants suffered from depressive symptoms at both baseline and 3-month follow-up. Higher CAHQ and BAI at both periods predicted depressive symptoms at three-month end. Being male, increased severity of CAHQ and BAI were risk factors of depressive symptoms. Psychiatric professionals must educate patients to manage auditory hallucinations and anxiety symptoms to decrease depressive symptoms.

Determination of (87)Sr/(86)Sr and δ(88/86)Sr ratios in plant materials using MC-ICP-MS.

A protocol for highly accurate and precise determination of Sr isotope ratios in plant materials, (87)Sr/(86)Sr and δ (88/86)Sr, by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) is presented in this study. An Eichrom Sr resin was used for matrix separation and an improved Zr empirical external normalization coupled with standard-sample bracketing method (Zr EEN-SSB) was applied to mass bias correction during Sr isotope MC-ICP-MS measurements. Potential influences of matrix elements, and polyatomic and isobaric interferences on the Sr isotopic determination were further evaluated using NIST SRM 987 Sr isotopic standard spiked with various amount of Ca, Mg, and Rb contents. Concentrations of Ca and Mg lower than 30 ng g(-1) or Rb < 2 ng g(-1) in 150 ng g(-1) Sr analyte were estimated to have only a minor effect on Sr isotope ratios determination. On the other hand, intensity differences between sample and standards (IntSample/IntStandards) represented a large δ (88/86)Sr deviation of <0.9 or >1.3, reflecting the significance of intensity bias attributed to different mass bias behavior. An apple leaf material, NIST SRM 1515, was adopted as the plant material for overall evaluation of sample digestion, matrix separation, and potential spectral interferences on the measurements of Sr isotope ratios. Our results suggest that the partially remaining organic compounds in the incomplete digestion would have a significant bias on the extraction chromatography procedure, resulting in sizable uncertainty in δ (88/86)Sr ratios. Thus, complete digestion of the organic-enriched materials is of great importance for efficiency assurance in matrix separation. Extraction chromatography works well for the total digested samples, where Ca, Mg, and Rb were efficiently removed. The obtained average (87)Sr/(86)Sr and δ (88/86)Sr values for the NIST SRM 1515 apple leaves are 0.71398 ± 0.00004 and 0.23 ± 0.03‰ (2SD, n = 10), respectively.

SCF(KMD) controls cytokinin signaling by regulating the degradation of type-B response regulators.

Cytokinins are plant hormones that play critical roles in growth and development. In Arabidopsis, the transcriptional response to cytokinin is regulated by action of type-B Arabidopsis response regulators (ARRs). Although central elements in the cytokinin signal transduction pathway have been identified, mechanisms controlling output remain to be elucidated. Here we demonstrate that a family of F-box proteins, called the kiss me deadly (KMD) family, targets type-B ARR proteins for degradation. KMD proteins form an S-phase kinase-associated PROTEIN1 (SKP1)/Cullin/F-box protein (SCF) E3 ubiquitin ligase complex and directly interact with type-B ARR proteins. Loss-of-function KMD mutants stabilize type-B ARRs and exhibit an enhanced cytokinin response. In contrast, plants with elevated KMD expression destabilize type-B ARR proteins leading to cytokinin insensitivity. Our results support a model in which an SCF(KMD) complex negatively regulates cytokinin responses by controlling levels of a key family of transcription factors.

Identification of cytokinin-responsive genes using microarray meta-analysis and RNA-Seq in Arabidopsis.

Cytokinins are N(6)-substituted adenine derivatives that play diverse roles in plant growth and development. We sought to define a robust set of genes regulated by cytokinin as well as to query the response of genes not represented on microarrays. To this end, we performed a meta-analysis of microarray data from a variety of cytokinin-treated samples and used RNA-seq to examine cytokinin-regulated gene expression in Arabidopsis (Arabidopsis thaliana). Microarray meta-analysis using 13 microarray experiments combined with empirically defined filtering criteria identified a set of 226 genes differentially regulated by cytokinin, a subset of which has previously been validated by other methods. RNA-seq validated about 73% of the up-regulated genes identified by this meta-analysis. In silico promoter analysis indicated an overrepresentation of type-B Arabidopsis response regulator binding elements, consistent with the role of type-B Arabidopsis response regulators as primary mediators of cytokinin-responsive gene expression. RNA-seq analysis identified 73 cytokinin-regulated genes that were not represented on the ATH1 microarray. Representative genes were verified using quantitative reverse transcription-polymerase chain reaction and NanoString analysis. Analysis of the genes identified reveals a substantial effect of cytokinin on genes encoding proteins involved in secondary metabolism, particularly those acting in flavonoid and phenylpropanoid biosynthesis, as well as in the regulation of redox state of the cell, particularly a set of glutaredoxin genes. Novel splicing events were found in members of some gene families that are known to play a role in cytokinin signaling or metabolism. The genes identified in this analysis represent a robust set of cytokinin-responsive genes that are useful in the analysis of cytokinin function in plants.

Functional characterization of type-B response regulators in the Arabidopsis cytokinin response.

Cytokinins play critical roles in plant growth and development, with the transcriptional response to cytokinin being mediated by the type-B response regulators. In Arabidopsis (Arabidopsis thaliana), type-B response regulators (ARABIDOPSIS RESPONSE REGULATORS [ARRs]) form three subfamilies based on phylogenic analysis, with subfamily 1 having seven members and subfamilies 2 and 3 each having two members. Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. To determine which type-B ARRs can functionally substitute for the subfamily 1 members ARR1 or ARR12, we expressed different type-B ARRs from the ARR1 promoter and assayed their ability to rescue arr1 arr12 double mutant phenotypes. ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. Expression of ARR10 from the ARR1 promoter results in cytokinin hypersensitivity and enhances shoot regeneration from callus tissue, correlating with enhanced stability of the ARR10 protein compared with the ARR1 protein. Examination of transfer DNA insertion mutants in subfamilies 2 and 3 revealed little effect on several well-characterized cytokinin responses. However, a member of subfamily 2, ARR21, restores cytokinin sensitivity to arr1 arr12 roots when expressed from the ARR1 promoter, indicating functional conservation of this divergent family member. Our results indicate that the type-B ARRs have diverged in function, such that some, but not all, can complement the arr1 arr12 mutant. In addition, our results indicate that type-B ARR expression profiles in the plant, along with posttranscriptional regulation, play significant roles in modulating their contribution to cytokinin signaling.

Urolithin-A Promotes CD8+ T Cell-mediated Cancer Immunosurveillance via FOXO1 Activation.

Naïve T cells are key players in cancer immunosurveillance, even though their function declines during tumor progression. Thus, interventions capable of sustaining the quality and function of naïve T cells are needed to improve cancer immunoprevention.In this context, we studied the capacity of Urolithin-A (UroA), a potent mitophagy inducer, to enhance T cell-mediated cancer immunosurveillance.We discovered that UroA improved the cancer immune response by activating the transcription factor FOXO1 in CD8+ T cell. Sustained FOXO1 activation promoted the expression of the adhesion molecule L-selectin (CD62L) resulting in the expansion of the naïve T cells population. We found that UroA reduces FOXO1 phosphorylation favoring its nuclear localization and transcriptional activity. Overall, our findings determine FOXO1 as a novel molecular target of UroA in CD8+ T cells and indicate UroA as promising immunomodulator to improve cancer immunosurveillance. SIGNIFICANCE: Urolithin-A, a potent mitophagy inducer, emerges as a promising tool to enhance cancer immunosurveillance by activating the FOXO1 transcription factor in CD8+ T cells. This activation promotes the expansion of naïve T cells, offering a novel avenue for improving cancer immune response and highlighting UroA as a potential immunomodulator for bolstering our body's defenses against cancer.

Enhancing the identification of voriconazole-associated hepatotoxicity by targeted metabolomics.

Voriconazole-associated hepatotoxicity is a common condition that generally manifests as elevated liver enzymes and can lead to drug discontinuation. Careful monitoring of voriconazole-associated hepatotoxicity is needed but there are no specific plasma biomarkers for this condition. Metabolomics has emerged as a promising technique for investigating biomarkers associated with drug-induced toxicity. The aim of this study was to use targeted metabolomics to evaluate seven endogenous metabolites as potential biomarkers of voriconazole-associated hepatotoxicity. Patients undergoing therapeutic drug monitoring of voriconazole were classified into a hepatotoxicity group (18 patients) or a control group (153 patients). Plasma samples were analysed using ultra-high-performance liquid chromatography coupled to mass spectrometry. Metabolite concentrations in the two groups were compared. Areas under the receiver operating characteristic (AUROC) curves generated from logistic regressions were used to correlate the concentrations of these seven metabolites with voriconazole trough concentrations and conventional liver biochemistry tests. Glycocholate and α-ketoglutarate levels were significantly higher in the hepatotoxicity group compared with the control group (false discovery rate-corrected P < 0.001 and P = 0.024, respectively). The metabolites glycocholate (AUROC = 0.795) and α-ketoglutarate (AUROC = 0.696) outperformed voriconazole trough concentrations (AUROC = 0.555) and approached the performance of alkaline phosphatase (AUROC = 0.876) and total bilirubin (AUROC = 0.815). A panel of glycocholate combined with voriconazole trough concentrations (AUROC = 0.827) substantially improved the performance of voriconazole trough concentrations alone in predicting hepatotoxicity. In conclusion, the panel integrating glycocholate with voriconazole trough concentrations has great potential for identifying voriconazole-associated hepatotoxicity.

Functional characterization of the GATA transcription factors GNC and CGA1 reveals their key role in chloroplast development, growth, and division in Arabidopsis.

Chloroplasts develop from proplastids in a process that requires the interplay of nuclear and chloroplast genomes, but key steps in this developmental process have yet to be elucidated. Here, we show that the nucleus-localized transcription factors GATA NITRATE-INDUCIBLE CARBON-METABOLISM-INVOLVED (GNC) and CYTOKININ-RESPONSIVE GATA1 (CGA1) regulate chloroplast development, growth, and division in Arabidopsis (Arabidopsis thaliana). GNC and CGA1 are highly expressed in green tissues, and the phytohormone cytokinin regulates their expression. A gnc cga1 mutant exhibits a reduction in overall chlorophyll levels as well as in chloroplast size in the hypocotyl. Ectopic overexpression of either GNC or CGA1 promotes chloroplast biogenesis in hypocotyl cortex and root pericycle cells, based on increases in the number and size of the chloroplasts, and also results in expanded zones of chloroplast production into the epidermis of hypocotyls and cotyledons and into the cortex of roots. Ectopic overexpression also promotes the development of etioplasts from proplastids in dark-grown seedlings, subsequently enhancing the deetiolation process. Inducible expression of GNC demonstrates that GNC-mediated chloroplast biogenesis can be regulated postembryonically, notably so for chloroplast production in cotyledon epidermal cells. Analysis of the gnc cga1 loss-of-function and overexpression lines supports a role for these transcription factors in regulating the effects of cytokinin on chloroplast division. These data support a model in which GNC and CGA1 serve as two of the master transcriptional regulators of chloroplast biogenesis, acting downstream of cytokinin and mediating the development of chloroplasts from proplastids and enhancing chloroplast growth and division in specific tissues.

Mitochondria Dictate Function and Fate of HSCs and T Cells.

Hematopoietic stem cells (HSC) and T cells are intimately related, lineage-dependent cell populations that are extensively used as therapeutic products for the treatment of hematologic malignancies and certain types of solid tumors. These cellular therapies can be life-saving treatments; however, their efficacies are often limited by factors influencing their activity and cellular properties. Among these factors is mitochondrial metabolism, which influences the function and fate commitment of both HSCs and T cells. Mitochondria, besides being the "cellular powerhouse," provide metabolic intermediates that are used as substrates for epigenetic modifications and chromatin remodeling, thus, driving cell fate decisions during differentiation. Moreover, mitochondrial fitness and mitochondrial quality control mechanisms are closely related to cellular function, and impairment of these mitochondrial properties associates with cellular dysfunction due to factors such as T-cell exhaustion and aging. Here, we give an overview of the role of mitochondria in shaping the behavior of these lineage-related cell populations. Moreover, we discuss the potential of novel mitochondria-targeting strategies for enhancing HSC- and T cell-based cancer immunotherapies and highlight how design and application of such approaches requires consideration of the metabolic similarities and differences between HSCs and T cells. See related article on p. 1302.

Induction of mitochondrial recycling reverts age-associated decline of the hematopoietic and immune systems.

Aging compromises hematopoietic and immune system functions, making older adults especially susceptible to hematopoietic failure, infections and tumor development, and thus representing an important medical target for a broad range of diseases. During aging, hematopoietic stem cells (HSCs) lose their blood reconstitution capability and commit preferentially toward the myeloid lineage (myeloid bias)1,2. These processes are accompanied by an aberrant accumulation of mitochondria in HSCs3. The administration of the mitochondrial modulator urolithin A corrects mitochondrial function in HSCs and completely restores the blood reconstitution capability of 'old' HSCs. Moreover, urolithin A-supplemented food restores lymphoid compartments, boosts HSC function and improves the immune response against viral infection in old mice. Altogether our results demonstrate that boosting mitochondrial recycling reverts the aging phenotype in the hematopoietic and immune systems.

The Relationship between Depressive Symptoms, Rumination, and Suicide Ideation in Patients with Depression.

The relationship between suicide and rumination in depression is a recent topic of attention in mental health. The purpose of this study was to investigate the relationship between demographic variables, depressive symptoms, rumination, and suicide ideation in patients with depression, as well as the predictors of suicide ideation. RESEARCH DESIGN: A cross-sectional study of 95 subjects with depression recruited intentionally from the psychiatric ward of Tzu Chi Hospital. The questionnaire included demographic data, the Beck Depression Inventory-II, the Ruminative Response Scale, and the Beck Scale for Suicide Ideation. Independent sample t-test, Pearson product difference correlation, and the stepwise regression test were adopted for data analysis. RESULTS: Age (r = -0.41, p < 0.01), age at diagnosis (r = -0.34, p < 0.01), and sleep duration (r = -0.25, p < 0.05) were negatively correlated with rumination-reflection. The depressive symptoms (r = 0.72, p < 0.01) were positively correlated with rumination, whereas rumination (r = 0.57, p < 0.01) and suicide ideation were positively correlated. Depressive symptoms and rumination could predict suicide ideation, and the effective explanatory power reached 60%. CONCLUSIONS: If the patient with depression was younger or the patient was diagnosed at a younger age, the depressive symptoms of the reflection subscale of rumination thinking and suicide ideation were more serious. Our results indicate that clinicians who care for patients with depression should be aware of rumination and its impact on suicide ideation, specifically in younger patients.

Integrin αIIbß3 outside-in signaling activates human platelets through serine 24 phosphorylation of Disabled-2.

BACKGROUND: Bidirectional integrin αIIbß3 signaling is essential for platelet activation. The platelet adaptor protein Disabled-2 (Dab2) is a key regulator of integrin signaling and is phosphorylated at serine 24 in eukaryotic cells. However, the mechanistic insight and function of Dab2-serine 24 phosphorylation (Dab2-pSer24) in platelet biology are barely understood. This study aimed to define whether and how Dab2 is phosphorylated at Ser24 during platelet activation and to investigate the effect of Dab2-pSer24 on platelet function. RESULTS: An antibody with confirmed specificity for Dab2-pSer24 was generated. By using this antibody as a tool, we showed that protein kinase C (PKC)-mediated Dab2-pSer24 was a conservative signaling event when human platelets were activated by the platelet agonists such as thrombin, collagen, ADP, 12-O-tetradecanoylphorbol-13-acetate, and the thromboxane A2 activator U46619. The agonists-stimulated Dab2-pSer24 was attenuated by pretreatment of platelets with the RGDS peptide which inhibits integrin outside-in signaling by competitive binding of integrin αIIb with fibrinogen. Direct activation of platelet integrin outside-in signaling by combined treatment of platelets with manganese dichloride and fibrinogen or by spreading of platelets on fibrinogen also resulted in Dab2-pSer24. These findings implicate that Dab2-pSer24 was associated with the outside-in signaling of integrin. Further analysis revealed that Dab2-pSer24 was downstream of Src-PKC-axis and phospholipase D1 underlying the integrin αIIbß3 outside-in signaling. A membrane penetrating peptide R11-Ser24 which contained 11 repeats of arginine linked to the Dab2-Ser24 phosphorylation site and its flanking sequences (RRRRRRRRRRR19APKAPSKKEKK29) and the R11-S24A peptide with Ser24Ala mutation were designed to elucidate the functions of Dab2-pSer24. R11-Ser24 but not R11-S24A inhibited agonists-stimulated Dab2-pSer24 and consequently suppressed platelet spreading on fibrinogen, with no effect on platelet aggregation and fibrinogen binding. Notably, Ser24 and the previously reported Ser723 phosphorylation (Dab2-pSer723) occurred exclusively in a single Dab2 molecule and resulted in distinctive subcellular distribution and function of Dab2. Dab2-pSer723 was mainly distributed in the cytosol of activated platelets and associated with integrin inside-out signaling, while Dab2-pSer24 was mainly distributed in the membrane fraction of activated platelets and associated with integrin outside-in signaling. CONCLUSIONS: These findings demonstrate for the first time that Dab2-pSer24 is conservative in integrin αIIbß3 outside-in signaling during platelet activation and plays a novel role in the control of cytoskeleton reorganization and platelet spreading on fibrinogen.

Elucidation of the core betalain biosynthesis pathway in Amaranthus tricolor.

Amaranthus tricolor L., a vegetable Amaranthus species, is an economically important crop containing large amounts of betalains. Betalains are natural antioxidants and can be classified into betacyanins and betaxanthins, with red and yellow colors, respectively. A. tricolor cultivars with varying betalain contents, leading to striking red to green coloration, have been commercially produced. However, the molecular differences underlying betalain biosynthesis in various cultivars of A. tricolor remain largely unknown. In this study, A. tricolor cultivars with different colors were chosen for comparative transcriptome analysis. The elevated expression of AmCYP76AD1 in a red-leaf cultivar of A. tricolor was proposed to play a key role in producing red betalain pigments. The functions of AmCYP76AD1, AmDODAα1, AmDODAα2, and AmcDOPA5GT were also characterized through the heterologous engineering of betalain pigments in Nicotiana benthamiana. Moreover, high and low L-DOPA 4,5-dioxygenase activities of AmDODAα1 and AmDODAα2, respectively, were confirmed through in vitro enzymatic assays. Thus, comparative transcriptome analysis combined with functional and enzymatic studies allowed the construction of a core betalain biosynthesis pathway of A. tricolor. These results not only provide novel insights into betalain biosynthesis and evolution in A. tricolor but also provide a basal framework for examining genes related to betalain biosynthesis among different species of Amaranthaceae.

Tumor-localized ligation of CD3 and CD28 with systemic regulatory T-cell depletion induces potent innate and adaptive antitumor responses.

PURPOSE: Tumor-localized activation of immune cells by membrane-tethered anti-CD3 antibodies (CD3L) is under investigation to treat poorly immunogenic tumors. Here we sought to elucidate the mechanism of antitumor immunity elicited by CD3L. EXPERIMENTAL DESIGN: CD3L and CD86 were expressed on poorly immunogenic B16 melanoma cells (B16/3L86 cells) and the effect of various lymphocytes, including CD4(+) and CD8(+) T cells, natural killer T (NKT) cells, and regulatory T cells, on antitumor activity was investigated. RESULTS: B16/3L86 cells activated naïve T cells; suppressed tumor growth in subcutaneous, peritoneal, and metastasis models; and protected mice from rechallenge with B16 melanoma cells. However, in vivo antitumor activity against primary B16/3L86 tumors unexpectedly depended on NKT cells rather than CD4(+) or CD8(+) T cells. Treatment of mice with low-dose cyclophosphamide or anti-CD25 antibody to deplete regulatory T cells unmasked latent T-cell antitumor activity; the number of activated CD8(+) T cells in tumors increased and B16/3L86 tumors were completely rejected in a CD8(+) and CD4(+) T-cell-dependent fashion. Furthermore, fibroblasts expressing CD3L and CD86 suppressed the growth of neighboring B16 cancer cells in vivo, and direct intratumoral injection of adenoviral vectors expressing CD3L and CD86 or CD3L and a membrane-tethered anti-CD28 antibody significantly suppressed the growth of subcutaneous tumors. CONCLUSIONS: Tumor-located ligation of CD3 and CD28 can activate both innate (NKT cells) and adaptive (CD4(+) and CD8(+) T cells) responses to create a tumor-destructive environment to control tumor growth, but modulation of regulatory T cells is necessary to unmask local adaptive antitumor responses.

Cell-to-Cell Spread of Dengue Viral RNA in Mosquito Cells.

Dengue virus (DENV) is an important mosquito-borne arbovirus that is particularly prevalent in tropical and subtropical areas of the world. The virus is generally ingested with a blood meal, replicates in host tissues, and disseminates into salivary glands for transmission to the next host. Membrane-bound vacuoles carrying DENV particles have been documented in mosquito cells and play a role in the cell-to-cell transmission of DENV2. C189 is one member of the tetraspanin family and generally increases its expression as one component of the vacuoles (C189-VCs) within C6/36 cells infected with DENV2. In the present study, we have further demonstrated via sucrose gradient centrifugation as well as magnetic immune isolation (MI) that the RNA of DENV2 was eventually carried by C189-VCs. In addition, viral RNA was shown to spread from donor to recipient cells in a coculture assay even when 20 mM NH4Cl was added to inhibit virus replication in the culture. In an alternate assay using the transwell system, viral RNA was only detected in recipient cells in the absence of 40 mM NH4Cl, suggesting that cell-cell contact is required for the intercellular spread of DENV2. In turn, the formation of viral synapse (VS) derived from aggregates of viral particles was frequently observed at sites of cell contact. Taken together, the formation of C189-VCs in C6/36 cells is induced by DENV2 infection, which may serve as a vehicle for transferring virions and also viral RNA to neighboring cells by cell-to-cell transmission after cell-cell contact. This finding provides insight into the understanding of viral spread between mosquito cells. It may also elucidate the benign persistent infection in mosquito cells and efficient dissemination of DENV infection within a mosquito vector.

Safety assessment of miraculin using in silico and in vitro digestibility analyses.

Miraculin is a glycoprotein with the ability to make sour substances taste sweet. The safety of miraculin has been evaluated using an approach proposed by the Food and Agriculture Organization of the United Nations and the World Health Organization for assessing the safety of novel proteins. Miraculin was shown to be fully and rapidly digested by pepsin in an in vitro digestibility assay. The proteomic analysis of miraculin's pepsin digests further corroborated that it is highly unlikely that any of the protein will remain intact within the gastrointestinal tract for potential absorption. The potential allergenicity and toxigenicity of miraculin, investigated using in silico bioinformatic analyses, demonstrated that miraculin does not represent a risk of allergy or toxicity to humans with low potential for cross-reactivity with other allergens. The results of a sensory study, characterizing the taste receptor activity of miraculin, showed that the taste-modifying effect of miraculin at the concentration intended for product development has a rapid onset and disappearance with no desensitizing impact on the receptor. Overall, the results of this study demonstrate that the use of miraculin to impact the sensory qualities of orally administered products with a bitter/sour taste profile is not associated with any safety concerns.

Synthesis, human telomerase inhibition and anti-proliferative studies of a series of 2,7-bis-substituted amido-anthraquinone derivatives.

Telomerase is important in tumor initiation and cellular immortalization. Given the striking correlations between telomerase activity and proliferation capacity in tumor cells, telomerase had been considered as a potentially important molecular target in cancer therapeutics. A series of 2,7-diamidoanthraquinone were designed and synthesized. They were evaluated for their effects on telomerase activity, hTERT expression, cell proliferations, and cytotoxicity. In the series, compounds (6, 10, 13, 16, 18, 19, 20-22, and 24) showed potent telomerase inhibitory activity, while compounds 19, 21, and 22 activated hTERT expression in normal human fibroblasts. The results indicated that 2,7-diamidoanthraquinones represent an important class of compounds for telomerase-related drug developments. Compounds 8, 16, 18, 26, and 32 were also selected by the NCI for Screening Program and demonstrated high anti-proliferative activity against 60 human cancer cell lines. Structure-activity relationships (SAR) study revealed that the test compounds with side chains two carbon spacer between amido and amine are important structural moiety for telomerase inhibition. Although the exact mechanism of how this amine group contributes to its activity is still unclear, however, the amine group in the extended arm of the bis-substituted anthraquinone might contribute to proper binding to the residues within the grove of G-quadruplex structure. Our results indicated that the 2,7-disubstituted amido-anthraquinones are potent telomerase inhibitors that have the potential to be further developed into novel anticancer chemotherapeutic agents.

A novel p53 paralogue mediates antioxidant defense of mosquito cells to survive dengue virus replication.

Mosquito cells allow dengue viruses (DENVs) to undergo replication without causing serious deleterious effects on the cells, leading to advantages for dissemination to other cells. Despite this, increased accumulation of reactive oxygen species (ROS) is usually detected in C6/36 cells with DENV2 infection as shown in mammalian cells. Uniquely, oxidative stress caused by the ROS is alleviated by eliciting antioxidant defense which leads to protection of mosquito cells from the infection. In the present study, a novel p53 paralogue (p53-2) was identified and proved to be regulated in C6/36 cells with DENV2 infection. With a gene-knockdown technique, p53-2 was demonstrated to transcribe catalase which plays a critical role in reducing ROS accumulation and the death rate of infected cells. Ecologically, a higher survival rate of mosquito cells is a prerequisite for prosperous production of viral progeny, allowing infected mosquitoes to remain healthy and active for virus transmission.