Entosis implicates a new role for P53 in microcephaly pathogenesis, beyond apoptosis.

Entosis, a form of cell cannibalism, is a newly discovered pathogenic mechanism leading to the development of small brains, termed microcephaly, in which P53 activation was found to play a major role. Microcephaly with entosis, found in Pals1 mutant mice, displays P53 activation that promotes entosis and apoptotic cell death. This previously unappreciated pathogenic mechanism represents a novel cellular dynamic in dividing cortical progenitors which is responsible for cell loss. To date, various recent models of microcephaly have bolstered the importance of P53 activation in cell death leading to microcephaly. P53 activation caused by mitotic delay or DNA damage manifests apoptotic cell death which can be suppressed by P53 removal in these animal models. Such genetic studies attest P53 activation as quality control meant to eliminate genomically unfit cells with minimal involvement in the actual function of microcephaly associated genes. In this review, we summarize the known role of P53 activation in a variety of microcephaly models and introduce a novel mechanism wherein entotic cell cannibalism in neural progenitors is triggered by P53 activation.

Abnormal activation of Yap/Taz contributes to the pathogenesis of tuberous sclerosis complex.

The multi-systemic genetic disorder tuberous sclerosis complex (TSC) impacts multiple neurodevelopmental processes including neuronal morphogenesis, neuronal migration, myelination and gliogenesis. These alterations contribute to the development of cerebral cortex abnormalities and malformations. Although TSC is caused by mTORC1 hyperactivation, cognitive and behavioral impairments are not improved through mTORC1 targeting, making the study of the downstream effectors of this complex important for understanding the mechanisms underlying TSC. As mTORC1 has been shown to promote the activity of the transcriptional co-activator Yap, we hypothesized that altered Yap/Taz signaling contributes to the pathogenesis of TSC. We first observed that the levels of Yap/Taz are increased in human cortical tuber samples and in embryonic cortices of Tsc2 conditional knockout (cKO) mice. Next, to determine how abnormal upregulation of Yap/Taz impacts the neuropathology of TSC, we deleted Yap/Taz in Tsc2 cKO mice. Importantly, Yap/Taz/Tsc2 triple conditional knockout (tcKO) animals show reduced cortical thickness and cortical neuron cell size, despite the persistence of high mTORC1 activity, suggesting that Yap/Taz play a downstream role in cytomegaly. Furthermore, Yap/Taz/Tsc2 tcKO significantly restored cortical and hippocampal lamination defects and reduced hippocampal heterotopia formation. Finally, the loss of Yap/Taz increased the distribution of myelin basic protein in Tsc2 cKO animals, consistent with an improvement in myelination. Overall, our results indicate that targeting Yap/Taz lessens the severity of neuropathology in a TSC animal model. This study is the first to implicate Yap/Taz as contributors to cortical pathogenesis in TSC and therefore as potential novel targets in the treatment of this disorder.

The autoimmune response induced by α-synuclein peptides drives neuronal cell death and glial cell activation.

Parkinson's disease (PD) is a progressive neurodegenerative disorder associated with the loss of dopaminergic neurons and neuroinflammation. Recent studies have identified a role of T cells in the pathogenesis of PD. Additionally, these studies suggested that α-synuclein (α-Syn) is related to abnormal T-cell responses and may act as an epitope and trigger autoimmune T-cell responses. However, it is unclear whether the α-Syn-mediated autoimmune response occurs and whether it is related to neuronal cell death and glial cell activation. In this study, we investigated the autoimmune T-cell response induced by α-Syn peptides and evaluated the neurotoxic effect of the α-Syn peptide-mediated autoimmune response. The immunization of mice with α-Syn peptides resulted in enhanced autoimmune responses, such as the peptide recall response, polarization toward Th1/Th17 cells, and regulatory T cell imbalance. Furthermore, the α-Syn autoimmune response led to the death of primary neurons cocultured with splenocytes. Treatment with conditioned media from α-Syn peptide-immunized splenocytes induced microglia and toxic A1-type astrocyte activation. Taken together, our results provide evidence of the potential role of the α-Syn-initiated autoimmune response and its contribution to neuronal cell death and glial cell activation.

The artificial amino acid change in the sialic acid-binding domain of the hemagglutinin neuraminidase of newcastle disease virus increases its specificity to HCT 116 colorectal cancer cells and tumor suppression effect.

BACKGROUND: Oncolytic viruses are being studied and developed as novel cancer treatments. Using directed evolution technology, structural modification of the viral surface protein increases the specificity of the oncolytic virus for a particular cancer cell. Newcastle disease virus (NDV) does not show specificity for certain types of cancer cells during infection; therefore, it has low cancer cell specificity. Hemagglutinin is an NDV receptor-binding protein on the cell surface that determines host cell tropism. NDV selectivity for specific cancer cells can be increased by artificial amino acid changes in hemagglutinin neuraminidase HN proteins via directed evolution, leading to improved therapeutic effects. METHODS: Sialic acid-binding sites (H domains) of the HN protein mutant library were generated using error-prone PCR. Variants of the H domain protein were screened by enzyme-linked immunosorbent assay using HCT 116 cancer cell surface molecules. The mutant S519G H domain protein showed the highest affinity for the surface protein of HCT 116 cells compared to that of different types of cancer cells. This showed that the S519G mutant H domain protein gene replaced the same part of the original HN protein gene, and S519G mutant recombinant NDV (rNDV) was constructed and recovered. S519G rNDV cancer cell killing effects were tested using the MTT assay with various cancer cell types, and the tumor suppression effect of the S519G mutant rNDV was tested in a xenograft mouse model implanted with cancer cells, including HCT 116 cells. RESULTS: S519G rNDV showed increased specificity and enhanced killing ability of HCT 116 cells among various cancer cells and a stronger suppressive effect on tumor growth than the original recombinant NDV. Directed evolution using an artificial amino acid change in the NDV HN (S519G mutant) protein increased its specificity and oncolytic effect in colorectal cancer without changing its virulence. CONCLUSION: These results provide a new methodology for the use of directed evolution technology for more effective oncolytic virus development.

Effects of 3S business intelligence systems for nursing students: a repeated-measures randomized control trial.

BACKGROUND: The growing need for healthcare services as a result of a consistently rising prevalence of chronic diseases and rapid population aging calls for a new set of activities and practices. Therefore, we developed a program-3S (Simple, Smart, and Speed) Business Intelligence Systems (3S-BIS), which is an ERP software system that helps nursing business to support nursing entrepreneurship -and analyzed its effects on nursing students. METHODS: A repeated-measures randomized controlled trial was performed with two groups: experimental (n = 29) and control (n = 30) groups. The former group underwent the five-day 3S-BIS education program. Each session comprised four components: lectures 1 and 2, simulation case study, and debriefing. Post-tests were performed immediately post-intervention and four and eight weeks later. The effectiveness was measured using the following variables: simulation design assessment, evaluation of educational practices in simulation, education satisfaction, self-efficacy for learning, and entrepreneurship. The differences before and after intervention between the experimental and control groups were analyzed using the Friedman test. The Mann-Whitney U test was used for comparisons between groups at each time point, and the Wilcoxon signed-rank test was used for comparisons within groups at each time point. RESULTS: Post-intervention (8 weeks after intervention), the experimental group demonstrated higher simulation design assessment (z = -3.88, p = < .001), evaluation of educational practices in simulation (z = -3.34, p = .001), education satisfaction (z = -3.11, p = .002), self-efficacy for learning (z = -3.04, p = .002), and entrepreneurship (z = -2.15, p = .031) compared to controls. Furthermore, simulation design assessment score in the experimental group significantly differed between T1 (immediately after intervention) and T0 (baseline), and between T3 (8 weeks after intervention) and T0. Evaluation of educational practices in the simulation, education satisfaction, and self-efficacy also significantly differed between T1 and T0, and between T3 and T0. Entrepreneurship significantly differed between T3 and T2 (4 weeks after intervention), and between T3 and T0. CONCLUSIONS: The 3S-BIS program contributes to enhancing nursing start-up competency. Subsequent studies should evaluate the effects of the program on nurses who work in home healthcare services.

Identifying the suicidal ideation risk group among older adults in rural areas: Developing a predictive model using machine learning methods.

AIMS: The aim of this study was to develop a predictive model that can identify the suicidal ideation risk group among older adults in rural areas using machine learning methods. DESIGN: This study applied an exploratory, descriptive and cross-sectional design. METHODS: The participants were older adults (N = 650) aged over 65 living in rural areas of South Korea. Self-report questionnaires were used to collect the demographics, suicidal ideation, depression, socioeconomic information and basic health information from September to October 2020. The collected data were analysed using machine learning methods with R statistical software 4.1.0. RESULTS: The predictive models indicated that depression, pain, age and loneliness were significant factors of suicidal ideation. Good performance was observed based on the area under the receiver operating characteristic curve in the decision tree, random forest and logistic regression. Finally, the evaluation of model performance indicated moderate to high sensitivity and specificity. CONCLUSION: The predictive models using machine learning methods may be useful to predict the risk of suicidal ideation. Furthermore, depression with pain, age and feelings of loneliness should be included in the initial screening to assess suicide risk among older adults in rural areas. IMPACT: Identifying suicidal risk among older adults is challenging. Thus, employing predictive models that can assess depression, pain, age and loneliness can enable public healthcare providers to detect suicidal risk groups. Particularly, the presented models from this study can facilitate healthcare providers with initiating early interventions to prevent suicide among older adults in clinical and community nursing care settings. REPORTING METHOD: The reporting of this study (Observational, cross-sectional study) conforms to the STROBE statement. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution. This study did not involve patients, service users, caregivers or members of the public. IMPLICATION FOR THE PROFESSION AND/OR PATIENTS CARE: Applying this model may help to prevent geriatric suicide because the nursing staff will have a greater awareness regarding the suicide ideation risk of older adults, thereby reducing the possibility of their suicide.

CRIF1 siRNA-Encapsulated PLGA Nanoparticles Suppress Tumor Growth in MCF-7 Human Breast Cancer Cells.

Mitochondrial oxidative phosphorylation (OXPHOS) system dysfunction in cancer cells has been exploited as a target for anti-cancer therapeutic intervention. The downregulation of CR6-interacting factor 1 (CRIF1), an essential mito-ribosomal factor, can impair mitochondrial function in various cell types. In this study, we investigated whether CRIF1 deficiency induced by siRNA and siRNA nanoparticles could suppress MCF-7 breast cancer growth and tumor development, respectively. Our results showed that CRIF1 silencing decreased the assembly of mitochondrial OXPHOS complexes I and II, which induced mitochondrial dysfunction, mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential depolarization, and excessive mitochondrial fission. CRIF1 inhibition reduced p53-induced glycolysis and apoptosis regulator (TIGAR) expression, as well as NADPH synthesis, leading to additional increases in ROS production. The downregulation of CRIF1 suppressed cell proliferation and inhibited cell migration through the induction of G0/G1 phase cell cycle arrest in MCF-7 breast cancer cells. Similarly, the intratumoral injection of CRIF1 siRNA-encapsulated PLGA nanoparticles inhibited tumor growth, downregulated the assembly of mitochondrial OXPHOS complexes I and II, and induced the expression of cell cycle protein markers (p53, p21, and p16) in MCF-7 xenograft mice. Thus, the inhibition of mitochondrial OXPHOS protein synthesis through CRIF1 deletion destroyed mitochondrial function, leading to elevated ROS levels and inducing antitumor effects in MCF-7 cells.

Cross-Activation of Regulatory T Cells by Self Antigens Limits Self-Reactive and Activated CD8+ T Cell Responses.

The interaction between regulatory T (Treg) cells and self-reactive T cells is a crucial mechanism for maintaining immune tolerance. In this study, we investigated the cross-activation of Treg cells by self-antigens and its impact on self-reactive CD8+ T cell responses, with a focus on the P53 signaling pathway. We discovered that major histocompatibility complex (MHC) I-restricted self-peptides not only activated CD8+ T cells but also induced the delayed proliferation of Treg cells. Following HLA-A*0201-restricted Melan-A-specific (pMelan) CD8+ T cells, we observed the direct expansion of Treg cells and concurrent suppression of pMelan+CD8+ T cell proliferation upon stimulation with Melan-A peptide. Transcriptome analysis revealed no significant alterations in specific signaling pathways in pMelan+CD8+ T cells that were co-cultured with activated Treg cells. However, there was a noticeable upregulation of genes involved in P53 accumulation, a critical regulator of cell survival and apoptosis. Consistent with such observation, the blockade of P53 induced a continuous proliferation of pMelan+CD8+ T cells. The concurrent stimulation of Treg cells through self-reactive TCRs by self-antigens provides insights into the immune system's ability to control activated self-reactive CD8+ T cells as part of peripheral tolerance, highlighting the intricate interplay between Treg cells and CD8+ T cells and implicating therapeutic interventions in autoimmune diseases and cancer immunotherapy.

The role of Hippo-YAP/TAZ signaling in brain development.

In order for our complex nervous system to develop normally, both precise spatial and temporal regulation of a number of different signaling pathways is critical. During both early embryogenesis and in organ development, one pathway that has been repeatedly implicated is the Hippo-YAP/TAZ signaling pathway. The paralogs YAP and TAZ are transcriptional co-activators that play an important role in cell proliferation, cell differentiation, and organ growth. Regulation of these proteins by the Hippo kinase cascade is therefore important for normal development. In this article, we review the growing field of research surrounding the role of Hippo-YAP/TAZ signaling in normal and atypical brain development. Starting from the development of the neural tube to the development and refinement of the cerebral cortex, cerebellum, and ventricular system, we address the typical role of these transcriptional co-activators, the functional consequences that manipulation of YAP/TAZ and their upstream regulators have on brain development, and where further research may be of benefit.

De novo variants in MPP5 cause global developmental delay and behavioral changes.

Membrane Protein Palmitoylated 5 (MPP5) is a highly conserved apical complex protein essential for cell polarity, fate and survival. Defects in cell polarity are associated with neurologic disorders including autism and microcephaly. MPP5 is essential for neurogenesis in animal models, but human variants leading to neurologic impairment have not been described. We identified three patients with heterozygous MPP5 de novo variants (DNV) and global developmental delay (GDD) and compared their phenotypes and magnetic resonance imaging (MRI) to ascertain how MPP5 DNV leads to GDD. All three patients with MPP5 DNV experienced GDD with language delay/regression and behavioral changes. MRI ranged from normal to decreased gyral folding and microcephaly. The effects of MPP5 depletion on the developing brain were assessed by creating a heterozygous conditional knock out (het CKO) murine model with central nervous system (CNS)-specific Nestin-Cre drivers. In the het CKO model, Mpp5 depletion led to microcephaly, decreased cerebellar volume and cortical thickness. Het CKO mice had decreased ependymal cells and Mpp5 at the apical surface of cortical ventricular zone compared with wild type. Het CKO mice also failed to maintain progenitor pools essential for neurogenesis. The proportion of cortical cells undergoing apoptotic cell death increased, suggesting that cell death reduces progenitor population and neuron number. Het CKO mice also showed behavioral changes, similar to our patients. To our knowledge, this is the first report to show that variants in MPP5 are associated with GDD, behavioral abnormalities and language regression/delay. Murine modeling shows that neurogenesis is likely altered in these individuals, with cell death and skewed cellular composition playing significant roles.

Yap/Taz are required for establishing the cerebellar radial glia scaffold and proper foliation.

Yap/Taz are well-established downstream effectors of the Hippo pathway, known to regulate organ size by directing proliferation and apoptosis. Although the functions of Yap/Taz have been extensively studied, little is known about their role in brain development. Here, through genetic ablation, we show that Yap/Taz are required for cerebellar morphogenesis. Yap/Taz deletion in neural progenitors causes defects in secondary fissure formation, leading to abnormal folia development. Although they seemed very likely to serve an important function in the development of cerebellar granule cell precursors, Yap/Taz are dispensable for their proliferation. Furthermore, Yap/Taz loss does not rescue the medulloblastoma phenotype caused by constitutively active Smoothened. Importantly, Yap/Taz are highly expressed in radial glia and play a crucial role in establishing the radial scaffold and cellular polarity of neural progenitors during embryogenesis. We found that Yap/Taz are necessary to establish and maintain junctional integrity of cerebellar neuroepithelium as prominent junction proteins are not maintained at the apical junction in the absence of Yap/Taz. Our study identifies a novel function of Yap/Taz in cerebellar foliation and finds that they are required to establish the radial glia scaffold and junctional stability.

Nearly complete deletion of BubR1 causes microcephaly through shortened mitosis and massive cell death.

BUB-related 1 (BubR1) encoded by Budding Uninhibited by Benzimidazole 1B (BUB1B) is a crucial mitotic checkpoint protein ensuring proper segregation of chromosomes during mitosis. Mutations of BUB1B are responsible for mosaic variegated aneuploidy (MVA), a human congenital disorder characterized by extensive abnormalities in chromosome number. Although microcephaly is a prominent feature of MVA carrying the BUB1B mutation, how BubR1 deficiency disturbs neural progenitor proliferation and neuronal output and leads to microcephaly is unknown. Here we show that conditional loss of BubR1 in mouse cerebral cortex recapitulates microcephaly. BubR1-deficient cortex includes a strikingly reduced number of late-born, but not of early-born, neurons, although BubR1 expression is substantially reduced from an early stage. Importantly, absence of BubR1 decreases the proportion of neural progenitors in mitosis, specifically in metaphase, suggesting shortened mitosis owing to premature chromosome segregation. In the BubR1 mutant, massive apoptotic cell death, which is likely due to the compromised genomic integrity that results from aberrant mitosis, depletes progenitors and neurons during neurogenesis. There is no apparent alteration in centrosome number, spindle formation or primary cilia, suggesting that the major effect of BubR1 deficiency on neural progenitors is to impair the mitotic checkpoint. This finding highlights the importance of the mitotic checkpoint in the pathogenesis of microcephaly. Furthermore, the ependymal cell layer does not form in the conditional knockout, revealing an unrecognized role of BubR1 in assuring the integrity of the ventricular system, which may account for the presence of hydrocephalus in some patients.

Distribution and genotypic analysis of Enterocytozoon bieneusi from wild boars in Korea.

Enterocytozoon bieneusi, an important microsporidian fungus, causes chronic diarrhea in humans and animals worldwide. Out of the 502 fecal samples from wild boars, 13 were positive for the E. bieneusi internal transcribed spacer region, with a prevalence of 2.6%. Six E. bieneusi genotypes, D, EbpC, and four novel KWB1-KWB4, were identified with zoonotic potential. Genotypes D (subgroup 1a) and EbpC (subgroup 1d) were first reported in Korean swine and Korea, respectively; KWB1-KWB4 (subgroup 1e) were most prevalent in this study. Because zoonotic genotypes have been identified, E. bieneusi transmission through wild boars must be closely monitored for proper prevention and treatment, despite their low prevalence. LAY SUMMARY: Enterocytozoon bieneusi is an important microsporidian fungus. Its sequences from wild boars were identified with zoonotic potential. Genotypes D and EbpC were first reported in Korean swine and Korea, respectively. E. bieneusi should be closely monitored to properly prevent and treat animals.

Ginkgonitroside, a new nitrophenyl glycoside and bioactive compounds from Ginkgo biloba leaves controlling adipocyte and osteoblast differentiation.

Eight compounds (1-8) including one novel nitrophenyl glycoside, ginkgonitroside (1) were isolated from the leaves of Ginkgo biloba, a popular medicinal plant. The structure of the new compound was characterized using extensive spectroscopic analyses via 1D and 2D NMR data interpretations, HR-ESIMS, and chemical transformation. To the best of our knowledge, the present study is the first to report the presence of nitrophenyl glycosides, which are relatively unique phytochemicals in natural products, in G. biloba. The isolated compounds (1-8) were examined for their effects on the regulation of mesenchymal stem cell (MSC) differentiation. Compounds 1-3 and 8 were able to suppress MSC differentiation toward adipocytes. In contrast, compounds 5 and 8 showed activity promoting osteogenic differentiation of MSCs. These findings demonstrate that the active compounds showed regulatory activity on MSC differentiation between adipocytes and osteocytes.

Ref-1 protects against FeCl3-induced thrombosis and tissue factor expression via the GSK3ß-NF-κB pathway.

Arterial thrombosis and its associated diseases are considered to constitute a major healthcare problem. Arterial thrombosis, defined as blood clot formation in an artery that interrupts blood circulation, is associated with many cardiovascular diseases. Oxidative stress is one of many important factors that aggravates the pathophysiological process of arterial thrombosis. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (Ref-1) has a multifunctional role in cells that includes the regulation of oxidative stress and anti-inflammatory function. The aim of this study was to investigate the therapeutic effect of adenovirus-mediated Ref-1 overexpression on arterial thrombosis induced by 60% FeCl3 solution in rats. Blood flow was measured to detect the time to occlusion, thrombus formation was detected by hematoxylin and eosin staining, reactive oxygen species (ROS) levels were detected by high-performance liquid chromatography, and the expression of tissue factor and other proteins was detected by Western blot. FeCl3 aggravated thrombus formation in carotid arteries and reduced the time to artery occlusion. Ref-1 significantly delayed arterial obstruction via the inhibition of thrombus formation, especially by downregulating tissue factor expression through the Akt-GSK3ß-NF-κB signaling pathway. Ref1 also reduced the expression of vascular inflammation markers ICAM-1 and VCAM1, and reduced the level of ROS that contributed to thrombus formation. The results showed that adenovirus-mediated Ref-1 overexpression reduced thrombus formation in the rat carotid artery. In summary, Ref-1 overexpression had anti-thrombotic effects in a carotid artery thrombosis model and could be a target for the treatment of arterial thrombosis.

Targeted deletion of Crb1/Crb2 in the optic vesicle models key features of leber congenital amaurosis 8.

The Crb1 and 2 (Crumbs homolog 1 & 2) genes encode large, single-pass transmembrane proteins essential for the apicobasal polarity and adhesion of epithelial cells. Crb1 mutations cause degenerative retinal diseases in humans, including Leber congenital amaurosis type 8 (LCA8) and retinitis pigmentosa type 12 (RP12). In LCA8, impaired photoreceptor development and/or survival is thought to cause blindness during early infancy, whereas, in RP12, progressive photoreceptor degeneration damages peripheral vision later in life. There are multiple animal models of RP12 pathology, but no experimental model of LCA8 recapitulates the full spectrum of its pathological features. To generate a mouse model of LCA8 and identify the functions of Crb1/2 in developing ocular tissues, we used an mRx-Cre driver to generate allelic combinations that enabled conditional gene ablation from the optic vesicle stage. In this series only Crb1/2 double knockout (dKO) mice exhibited characteristics of human LCA8 disease: locally thickened retina with spots devoid of cells, aberrant positioning of retinal cells, severely disrupted lamination, and depigmented retinal-pigmented epithelium. Retinal defects antedated E12.5, which is far earlier than the stage at which photoreceptor cells mainly differentiate. Most remarkably, Crb1/Crb2 dKO showed a severely attenuated electroretinogram at the eye opening stage. These results suggest that human LCA8 can be modeled in the mouse by simultaneously ablating Crb1/2 from the beginning of eye development. Importantly, they also indicate that LCA8 is caused by malfunction of retinal progenitor cells during early ocular development rather than by defective photoreceptor-Muller glial interaction, a mechanism proposed for RP12.

CRIF1 deficiency induced mitophagy via p66shc-regulated ROS in endothelial cells.

Inhibition of mitochondrial protein CR6 interacting factor 1 (CRIF1) disturbs mitochondrial function, depolarizes membrane potential, and increases reactive oxygen species (ROS) levels in endothelial cells. Impaired mitochondrial function accompanied by oxidative damage is a major contributor to the initiation of mitophagy. We hypothesized that CRIF1 deficiency-induced harmful effects may promote mitophagy, and explored the mechanism underlying this effect in human umbilical vein endothelial cells (HUVECs). Our results showed that CRIF1 downregulation not only induced the mitophagy-related markers LC3 (LC3-II/Ⅰ), PTEN-induced putative kinase 1 (PINK1) and parkin, but also stimulated redox enzyme p66shc expression. Scavenging mitochondrial ROS markedly blunted the CRIF1 deficiency-induced increase in p66shc expression. In addition, knockdown of p66shc inhibited the CRIF1 deletion-triggered mitochondrial ROS increase, membrane potential depolarization, and mitochondrial fusion. The restoration of mitochondrial dysfunction by p66shc downregulation also decreased CRIF1 deficiency-induced mitophagy, by elevating the levels of LC3-II/Ⅰ, PINK1 and parkin. These findings suggest that CRIF1 deficiency induces mitophagy via p66shc-regulated ROS in endothelial cells.

Ginkgobilol, a new diarylpentanoid and an osteogenic diarylpentanoid analog from Ginkgo biloba leaves.

Phytochemical analysis of methanol extracts of Ginkgo biloba leaves resulted in the isolation of a novel diarylpentanoid, ginkgobilol (1) and a known diarylpentanoid analog (2). The structure of the new compound was elucidated by analyzing NMR spectroscopic data and HR-ESIMS, and the absolute configuration was determined using gauge-including atomic orbital NMR chemical shift calculations, followed by DP4+ analysis and specific rotation value. Diarylpentanoids comprise two aromatic rings linked by a five-carbon bridge; these are relatively unique examples in natural products. To the best of our knowledge, the present study is the first to report the presence of diarylpentanoids in G. biloba. Compound 2 increased alkaline phosphatase (ALP) production in C3H10T1/2, a murine mesenchymal stem cell line, in a dose-dependent manner. The promotion of osteogenic differentiation by the active compound 2 mediated by induction of transcriptional ALP and osteopontin (OPN) gene expression was confirmed using quantitative real time polymerase chain reaction, thus indicating its remarkable bone formation activity.

Inhibitory Effects of AF-343, a Mixture of Cassia tora L., Ulmus pumila L., and Taraxacum officinale, on Compound 48/80-Mediated Allergic Responses in RBL-2H3 Cells.

The purpose of this study was to determine the antiallergic effects of AF-343, a mixture of natural plant extracts from Cassia tora L., Ulmus pumila L., and Taraxacum officinale, on rat basophilic leukemia (RBL-2H3) cells. The inhibitory effects on cell degranulation, proinflammatory cytokine secretion, and reactive oxygen species (ROS) production were studied in compound 48/80-treated RBL-2H3 cells. The bioactive compounds in AF-343 were also identified by HPLC-UV. AF-343 was found to effectively suppress compound 48/80-induced b-hexosaminidase release, and interleukin (IL)-4 and tumor necrosis factor-a (TNF-a) production in RBL-2H3 cells. In addition, AF-343 exhibited DPPH free radical scavenging effects in vitro (half-maximal inhibitory concentration (IC50) = 105 µg/mL) and potently inhibited compound 48/80-induced cellular ROS generation in a 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay. Specifically, treatment with AF-343 exerted stronger antioxidant effects in vitro and antiallergic effects in cells than treatment with three single natural plant extracts. Furthermore, AF-343 was observed to contain bioactive compounds, including catechin, aurantio-obtusin, and chicoric acid, which have been reported to elicit antiallergic responses. This study reveals that AF-343 attenuates allergic responses via suppression of b-hexosaminidase release, IL-4 and TNF-a secretion, and ROS generation, perhaps through mechanisms related to catechin, aurantio-obtusin, and chicoric acid. The results indicate that AF-343 can be considered a treatment for various allergic diseases.

RELT negatively regulates the early phase of the T-cell response in mice.

RELT (tumor necrosis factor receptor superfamily member 19-like, TNFRSF19L) is a TNFR superfamily member that is primarily expressed in immune cells and lymphoid tissues, but whose immunological function is not well-defined. Here, we show that RELT is expressed by naive T cells and DCs, and their activation or maturation decreases RELT expression. Using RELT knockout (RELT-/- ) mice, we demonstrate that RELT deficiency selectively promotes the homeostatic proliferation of CD4+ T cells but not CD8+ T cells, and enhances anti-tumor CD8+ T-cell responses. We also demonstrate, using an adoptive transfer model in which RELT is knocked-out in either the transferred transgenic CD8+ T cells or the recipient melanoma-bearing mice, that RELT on multiple immune cells limits the hyper-response of tumor-specific CD8+ T cells. Hyper-responsiveness of RELT-deficient T cells was induced by promoting their proliferation. Taken together, our findings suggest that RELT acts as a negative regulator that controls the early phase of T-cell activation probably by promoting T-cell apoptosis.