Bioactive peptides from scorpion venoms: therapeutic scaffolds and pharmacological tools / 中国天然药物

Evolution and natural selection have endowed animal venoms, including scorpion venoms, with a wide range of pharmacological properties. Consequently, scorpions, their venoms, and/or their body parts have been used since time immemorial in traditional medicines, especially in Africa and Asia. With respect to their pharmacological potential, bioactive peptides from scorpion venoms have become an important source of scientific research. With the rapid increase in the characterization of various components from scorpion venoms, a large number of peptides are identified with an aim of combating a myriad of emerging global health problems. Moreover, some scorpion venom-derived peptides have been established as potential scaffolds helpful for drug development. In this review, we summarize the promising scorpion venoms-derived peptides as drug candidates. Accordingly, we highlight the data and knowledge needed for continuous characterization and development of additional natural peptides from scorpion venoms, as potential drugs that can treat related diseases.

Development of a Therapeutic Peptide for Cachexia Suggests a Platform Approach for Drug-like Peptides.

During the development of a melanocortin (MC) peptide drug to treat the condition of cachexia (a hypermetabolic state producing lean body mass wasting), we were confronted with the need for peptide transport across the blood-brain barrier (BBB): the MC-4 receptors (MC4Rs) for metabolic rate control are located in the hypothalamus, i.e., behind the BBB. Using the term "peptides with BBB transport", we screened the medical literature like a peptide library. This revealed numerous "hits"-peptides with BBB transport and/or oral activity. We noted several features common to most peptides in this class, including a dipeptide sequence of nonpolar residues, primary structure cyclization (whole or partial), and a Pro-aromatic motif usually within the cyclized region. Based on this, we designed an MC4R antagonist peptide, TCMCB07, that successfully treated many forms of cachexia. As part of our pharmacokinetic characterization of TCMCB07, we discovered that hepatobiliary extraction from blood accounted for a majority of the circulating peptide's excretion. Further screening of the literature revealed that TCMCB07 is a member of a long-forgotten peptide class, showing active transport by a multi-specific bile salt carrier. Bile salt transport peptides have predictable pharmacokinetics, including BBB transport, but rapid hepatic clearance inhibited their development as drugs. TCMCB07 shares the general characteristics of the bile salt peptide class but with a much longer half-life of hours, not minutes. A change in its C-terminal amino acid sequence slows hepatic clearance. This modification is transferable to other peptides in this class, suggesting a platform approach for producing drug-like peptides.

Anticarin-β shows a promising anti-osteosarcoma effect by specifically inhibiting CCT4 to impair proteostasis

Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain proteostasis. The chaperonin T-complex protein ring complex (TRiC) contains eight paralogous subunits (CCT1-8), and assists the folding of as many as 10% of cytosolic proteome. TRiC is essential for the progression of some cancers, but the roles of TRiC subunits in osteosarcoma remain to be explored. Here, we show that CCT4/TRiC is significantly correlated in human osteosarcoma, and plays a critical role in osteosarcoma cell survival. We identify a compound anticarin-β that can specifically bind to and inhibit CCT4. Anticarin-β shows higher selectivity in cancer cells than in normal cells. Mechanistically, anticarin-β potently impedes CCT4-mediated STAT3 maturation. Anticarin-β displays remarkable antitumor efficacy in orthotopic and patient-derived xenograft models of osteosarcoma. Collectively, our data uncover a key role of CCT4 in osteosarcoma, and propose a promising treatment strategy for osteosarcoma by disrupting CCT4 and proteostasis.

SARS-CoV-2 causes human BBB injury and neuroinflammation indirectly in a linked organ chip platform

COVID-19 is a multi-system disease affecting many organs outside of the lungs, and patients generally develop varying degrees of neurological symptoms. Whereas, the pathogenesis underlying these neurological manifestations remains elusive. Although in vitro models and animal models are widely used in studies of SARS-CoV-2 infection, human organ models that can reflect the pathological alterations in a multi-organ context are still lacking. In this study, we propose a new strategy to probe the effects of SARS-CoV-2 on human brains in a linked alveolus-BBB organ chip platform. The new multi-organ platform allows to recapitulate the essential features of human alveolar-capillary barrier and blood-brain barrier in a microfluidic condition by co-culturing the organ-specific cells. The results reveal direct SARS-CoV-2 exposure has no obvious effects on BBB chip alone. While, infusion of endothelial medium from infected alveolus chips can cause BBB dysfunction and neuroinflammation on the linked chip platform, including brain endothelium disruption, glial cell activation and inflammatory cytokines release. These new findings suggest that SARS-CoV-2 could induce neuropathological alterations, which might not result from direct viral infection through hematogenous route, but rather likely from systemic inflammation following lung infection. This work provides a new strategy to study the virus-host interaction and neuropathology at an organ-organ context, which is not easily obtained by other in vitro models. This will facilitate to understand the neurological pathogenesis in SARS-CoV-2 and accelerate the development of new therapeutics. SUMMARYO_LIA linked human alveolus-BBB chip platform is established to explore the influences of SARS-CoV-2 on human brains in an organ-organ context. C_LIO_LISARS-CoV-2 infection could induce BBB injury and neuroinflammation. C_LIO_LIThe neuropathological changes are caused by SARS-CoV-2 indirectly, which might be mediated by systemic inflammation following lung infection, but probably not by direct viral neuroinvasion. C_LI

Impact of obesity on outcomes in patients with acute respiratory syndrome.

OBJECTIVES: We assessed the relationship between obesity and all-cause mortality in patients with acute respiratory distress syndrome (ARDS). METHODS: In this retrospective cohort study, patient data were extracted from the eICU Collaborative Research Database and the Medical Information Mart for Intensive Care Database III. Body mass index (BMI) was grouped according to World Health Organization classifications: underweight, normal weight, overweight, obese. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality related to obesity. RESULTS: Participants included 185 women and 233 men, mean age 70.7 ± 44.1 years and mean BMI 28.7 ± 8.1 kg/m2. Compared with normal weight patients, obese patients tended to be younger (60.1 ± 13.7 years) and included more women (51.3% vs. 49.0%). In the unadjusted model, HRs (95% CIs) of 30-day mortality for underweight, overweight, and obesity were 1.57 (0.76, 3.27), 0.64 (0.39, 1.08), and 4.83 (2.25, 10.35), respectively, compared with those for normal weight. After adjustment, HRs (95% CIs) of 30-day mortality for underweight, overweight, and obesity were 1.82 (0.85, 3.90), 0.59 (0.29, 1.20), and 3.85 (1.73, 8.57), respectively, compared with the reference group; 90-day and 1-year all-cause mortalities showed similar trends. CONCLUSIONS: Obesity was associated with increased all-cause mortality in patients with ARDS.

Identification and characterization of a novel elastase inhibitor from Hirudinaria manillensis / 中国天然药物

A large number of protease inhibitors have been found from leeches, which are essential in various physiological and biological processes. In the curret study, a novel elastase inhibitor was purified and characterized from the leech of Hirudinaria manillensis, which was named HMEI-A. Primary structure analysis showed that HMEI-A belonged to a new family of proteins. HMEI-A exerted inhibitory effects on elastase and showed potent abilities to inhibit elastase with an inhibition constant (K

Transferrin receptor is another receptor for SARS-CoV-2 entry

Angiotensin-converting enzyme 2 (ACE2) has been suggested as a receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry to cause coronavirus disease 2019 (COVID-19). However, no ACE2 inhibitors have shown definite beneficiaries for COVID-19 patients, applying the presence of another receptor for SARS-CoV-2 entry. Here we show that ACE2 knockout dose not completely block virus entry, while TfR directly interacts with virus Spike protein to mediate virus entry and SARS-CoV-2 can infect mice with over-expressed humanized transferrin receptor (TfR) and without humanized ACE2. TfR-virus co-localization is found both on the membranes and in the cytoplasma, suggesting SARS-CoV-2 transporting by TfR, the iron-transporting receptor shuttling between cell membranes and cytoplasma. Interfering TfR-Spike interaction blocks virus entry to exert significant anti-viral effects. Anti-TfR antibody (EC50 ~16.6 nM) shows promising anti-viral effects in mouse model. Collectively, this report indicates that TfR is another receptor for SARS-CoV-2 entry and a promising anti-COVID-19 target.

iTRAQ-based quantitative proteomic analysis provides insight for molecular mechanism of neuroticism.

BACKGROUND: Neuroticism is a core personality trait and a major risk factor for several mental and physical diseases, particularly in females, who score higher on neuroticism than men, on average. However, a better understanding of the expression profiles of proteins in the circulating blood of different neurotic female populations may help elucidate the intrinsic mechanism of neurotic personality and aid prevention strategies on mental and physical diseases associated with neuroticism. METHODS: In our study, female subjects were screened for inclusion by the Eysenck Personality Questionnaire (EPQ), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) scales and routine physical examination. Subjects who passed the examination and volunteered to participate were grouped by neuroticism using EPQ scores (0 and 1 = low neuroticism group; > 5 = high neuroticism group). Proteins in serum samples of the two neuroticism groups were identified using isobaric tags for relative and absolute quantification (iTRAQ) technology. RESULTS: A total of 410 proteins exhibited significant differences between high and low neuroticism, 236 proteins were significantly upregulated and 174 proteins were significantly downregulated. Combine the results of GO and KEGG enrichment analysis of differences proteins between high and low neuroticism with the PPI network, it could be observed that the Alpha-synuclein (SNCA), ATP7A protein (ATP7A), Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (GNG2), cyclin-dependent kinase 6 (CDK6), myeloperoxidase (MPO), azurocidin (AZU1), Histone H2B type 1-H (HIST1H2BH), Integrin alpha-M (ITGAM) and Matrix metalloproteinase-9 (MMP9) might participate in the intrinsic mechanism of neuroticism by regulating response to catecholamine stimulus, catecholamine metabolic process, limbic system development and transcriptional misregulation in cancer pathway. CONCLUSIONS: Our study revealed the characteristics of the neurotic personality proteome, which might be intrinsic mechanism of the neurotic population.

Intestinal Microbiota Is Altered in Patients with Gastric Cancer from Shanxi Province, China.

BACKGROUND: Many diseases have been associated with intestinal microbial dysbiosis. Host-microbial interactions regulate immune function, which influences the development of gastric cancer. AIMS: The aims were to investigate the characteristics of intestinal microbiota composition in gastric cancer patients and correlations between the intestinal microbiota and cellular immunity. METHODS: Fecal samples were collected from 116 gastric cancer patients and 88 healthy controls from Shanxi Province, China. The intestinal microbiota was investigated by 16S rRNA gene sequencing. Peripheral blood samples were also collected from the 66 gastric cancer patients and 46 healthy controls. The populations of peripheral T lymphocyte subpopulations and NK cells were analyzed by flow cytometry. RESULTS: The intestinal microbiota in gastric cancer patients was characterized by increased species richness, decreased butyrate-producing bacteria, and the enrichment of other symbiotic bacteria, especially Lactobacillus, Escherichia, and Klebsiella. Lactobacillus and Lachnospira were key species in the network of gastric cancer-associated bacterial genera. The combination of the genera Lachnospira, Lactobacillus, Streptococcus, Veillonella, and Tyzzerella_3 showed good performance in distinguishing gastric cancer patients from healthy controls. There was no significant difference in enterotype distribution between healthy controls and gastric cancer patients. The percentage of CD3+ T cells was positively correlated with the abundance of Lactobacillus and Streptococcus, and CD3+ T cells, CD4+ T cells, and NK cells were associated with Lachnospiraceae taxa. CONCLUSIONS: Our study revealed a dysbiotic intestinal microbiota in gastric cancer patients. The abundance of some intestinal bacterial genera was correlated with the population of peripheral immune cells.

3'-Methoxydaidzein exerts analgesic activity by inhibiting voltage-gated sodium channels / 中国天然药物

Isoflavones are widely consumed by people around the world in the form of soy products, dietary supplements and drugs. Many isoflavones or related crude extracts have been reported to exert pain-relief activities, but the mechanism remains unclear. Voltage-gated sodium channels (VGSCs) play important roles in excitability of pain sensing neurons and many of them are important nociceptors. Here, we report that several isoflavones including 3'-methoxydaidzein (3MOD), genistein (GEN) and daidzein (DAI) show abilities to block VGSCs and thus to attenuate chemicals and heat induced acute pain or chronic constriction injury (CCI) induced pain hypersensitivity in mice. Especially, 3MOD shows strong analgesic potential without inducing addiction through inhibiting subtypes Na1.7, Na1.8 and Na1.3 with the IC of 181 ± 14, 397 ± 26, and 505 ± 46 nmol·L, respectively, providing a promising compound or parent structure for the treatment of pain pathologies. This study reveals a pain-alleviating mechanism of dietary isoflavones and may provide a convenient avenue to alleviate pain.

In vivo antimalarial activity of synthetic hepcidin against Plasmodium berghei in mice / 中国天然药物

The present study was designed to investigate the antimalarial activity of synthetic hepcidin and its effect on cytokine secretion in mice infected with Plasmodium berghei. The mice were infected with P. berghei intravenously and treated with hepcidin according to 4-day suppression test and Rane's test. The serum levels of interleukins (IL-1β, IL-2, IL-6, IL-10, IL-12p70, and IL-17A), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the experimental mice were determined using a cytometric bead array (CBA) kit. The survival rate of the infected mice was also registered. Additionally, the serum iron, alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (BIL) were detected to evaluate liver functions. Hepcidin exerted direct anti-malarial function in vivo and increased survival rate in a dose-dependent manner. In addition, the secretion of T helper cell type 1 (Th1), Th2, and Th17 cytokines, TNF-α, and IFN-γ were inhibited by hepcidin. In conclusion, our results demonstrated that synthetic hepcidin exerts in vivo antimalarial activity and possesses anti-inflammatory function, which provides a basis for future design of new derivatives with ideal anti-malarial activity.

Dietary flavonoid luteolin attenuates uropathogenic Escherichia. Coli invasion of the urinary bladder.

Uropathogenic Escherichia coli (UPEC), the primary uropathogen, adhere to and invade bladder epithelial cells (BECs) to establish a successful urinary tract infection (UTI). Emerging antibiotic resistance requires novel nonantibiotic strategies. Our previous study indicated that luteolin attenuated adhesive and invasive abilities as well as cytotoxicity of UPEC on T24 BECs through down-regulating UPEC virulence factors. The aims of this study were to investigate the possible function of the flavonoid luteolin and the mechanisms by which luteolin functions in UPEC-induced bladder infection. Firstly, obvious reduction of UPEC invasion but not adhesion were observed in luteolin-pretreated 5637 and T24 BECs sa well as mice bladder via colony counting. The luteolin-mediated suppression of UPEC invasion was linked to elevated levels of intracellular cAMP induced by inhibiting the activity of cAMP-phosphodiesterases (cAMP-PDEs), which resulting activation of protein kinase A, thereby negatively regulating Rac1-GTPase-mediated actin polymerization. Furthermore, p38 MAPK was primarily and ERK1/2 was partially involved in luteolin-mediated suppression of UPEC invasion and actin polymerization, as confirmed with chemical activators of p38 MAPK and ERK1/2. These data suggest that luteolin can protect bladder epithelial cells against UPEC invasion. Therefore, luteolin or luteolin-rich products as dietary supplement may be beneficial to control the UPEC-related bladder infections, and cAMP-PDEs may be a therapy target for UTIs treatment. © 2016 BioFactors, 42(6):674-685, 2016.

Acclimation during space flight: effects on human emotion.

Recently, studies on the extent to which spaceflight affects the psychology of individuals has received attention. In order to reveal the mental challenges that humans face in space, we need practical viewpoints to integrate the psychological effects, behavior, performance and the environment itself for space exploration. The present review discusses the individual variables related to space psychology and manned spaceflight, in addition to their growing trends. These items include patterns of emotional changes in extreme environments and the approaches to evaluating emotions. Moreover, the review concludes with suggested future research on emotion during spaceflight and its analogs. These data and information are needed to plan for the exploration of the Moon and Mars, along with contributions to the construction of the international space station (ISS) and astronaut training.

[Functional Analysis of DNA Damage Repair Factor WDR70 and Its Mutation in Ovarian Cancer].

OBJECTIVES: To analyze the cellular function of the newly discovered DNA damage repair factor WDR70, and investigate the mutation in ovarian cancer to verify if function loss of the WDR70gene was associated with ovarian cancer. METHODS: The WDR70 gene was silenced by using siRNA technique or overexpressed its wild and mutation type by with lentivirus and plasmid in hunman cells. The subcellular localization and biochemical function of WDR70 was analyzes by indirect immunofluorescence and immunoblotting. The expression level of WDR70 and the mutations of its cDNA was checked with RT-PCR sequencing for 1 normal ovarian tissue and 16 ovarian cancer specimen. RESULTS: We found gene silencing of WDR70 or overexpression of WDR70 mutation type disrupts the phosphorylation level of homologous recombination functional protein RPA32 and the ability of recruitment at DNA damage site of recombinase RAD51, the loss of function of WDR70 also causes the elevation of the chromosome breakage in metaphase. Meanwhile, we also noticed that the existence of multiple mutations in genomic WDR70 in ovarian cancer specimen. CONCLUSIONS: Our results defined that in vitro system, WDR70 is a DNA damage repair gene, silencing of WDR70 or overexpression of WDR70 mutation type disrupts homologous recombination and chromosomal instability; the frequent mutations of WDR70 gene in genome of ovarian cancer specimens could also lead to DNA repair defeat and gene instability. Consequently WDR70 gene could represent an anti-cancer mechanism for ovarian cancer.

Protease inhibitor in scorpion (Mesobuthus eupeus) venom prolongs the biological activities of the crude venom / 中国天然药物

It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named MeKTT-1, belonged to Kunitz-type toxins subfamily. Native MeKTT-1 selectively inhibited trypsin with a Kivalue of 130 nmol·L(-1). Furthermore, MeKTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, MeKTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival.

Phenolic acids isolated from the fungus Schizophyllum commune exert analgesic activity by inhibiting voltage-gated sodium channels / 中国天然药物

The present study was designed to search for compounds with analgesic activity from the Schizophyllum commune (SC), which is widely consumed as edible and medicinal mushroom world. Thin layer chromatography (TLC), tosilica gel column chromatography, sephadex LH 20, and reverse-phase high performance liquid chromatography (RP-HPLC) were used to isolate and purify compounds from SC. Structural analysis of the isolated compounds was based on nuclear magnetic resonance (NMR). The effects of these compounds on voltage-gated sodium (NaV) channels were evaluated using patch clamp. The analgesic activity of these compounds was tested in two types of mouse pain models induced by noxious chemicals. Five phenolic acids identified from SC extracts in the present study included vanillic acid, m-hydroxybenzoic acid, o-hydroxybenzeneacetic acid, 3-hydroxy-5-methybenzoic acid, and p-hydroxybenzoic acid. They inhibited the activity of both tetrodotoxin-resistant (TTX-r) and tetrodotoxin-sensitive (TTX-s) NaV channels. All the compounds showed low selectivity on NaV channel subtypes. After intraperitoneal injection, three compounds of these compounds exerted analgesic activity in mice. In conclusion, phenolic acids identified in SC demonstrated analgesic activity, facilitating the mechanistic studies of SC in the treatment of neurasthenia.

Identification and characterization of a novel neuropeptide (neuropeptide Y-HS) from leech salivary gland of Haemadipsa sylvestris / 中国天然药物

The present study was designed to identify immunomodulatory components from the leech salivary gland of Haemadipsa sylvestris. The Sephadex G-50, Resource(TM) S column chromatography and reverse-phase high performance liquid chromatography (RP-HPLC) were used to isolate and purify the salivary gland extracts (SGE). Structural analysis of isolated compounds was based on Edman degradation and matrix assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). The cDNA encoding the precursor of the compound was cloned from the cDNA library of the salivary gland of H. sylvestris. The levels of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interferon γ (IFN-γ), interleukin-6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) were assayed using an enzyme-linked immunosorbent assay (ELISA). The effects on cell proliferation and cell viability were observed using MTT assay. A novel neuropeptide Y (Neuropeptide Y-HS) from the leech salivary gland of H. sylvestris was purified and characterized. It was composed of 36 amino acid residues and the amino acid sequence was determined to be FLEPPERPAVFTSVEQMKSYIKALNDYYLLLGRPRF-NH2, containing an amidated C-terminus. It showed significant inhibitory effects on the production of inflammatory cytokines including TNF-α, IFN-γ, IL-6, and MCP-1. Neuropeptide Y was identified from leeches for the first time. The presence of neuropeptide Y-HS in leech salivary gland may help get blood meal from hosts and inhibit inflammation.

Long-term total sleep deprivation decreases the default spontaneous activity and connectivity pattern in healthy male subjects: a resting-state fMRI study.

OBJECTIVE: The aim of this study is to use resting-state functional connectivity (rsFC) and amplitude of low-frequency fluctuation (ALFF) methods to explore intrinsic default-mode network (DMN) impairment after sleep deprivation (SD) and its relationships with clinical features. METHODS: Twelve healthy male subjects underwent resting-state functional magnetic resonance imaging twice: once following rested wakefulness (RW) and the other following 72 hours of total SD. Before the scans, all subjects underwent the attention network test (ANT). The independent component analysis (ICA), rsFC, and ALFF methods were used to examine intrinsic DMN impairment. Receiver operating characteristic (ROC) curve was used to distinguish SD status from RW status. RESULTS: Compared with RW subjects, SD subjects showed a lower accuracy rate (RW =96.83%, SD =77.67%; P<0.001), a slower reaction time (RW =695.92 ms; SD =799.18 ms; P=0.003), a higher lapse rate (RW =0.69%, SD =19.29%; P<0.001), and a higher intraindividual coefficient of variability in reaction time (RW =0.26, SD =0.33; P=0.021). The ICA method showed that, compared with RW subjects, SD subjects had decreased rsFC in the right inferior parietal lobule (IPL, BA40) and in the left precuneus (PrC)/posterior cingulate cortex (PCC) (BA30, 31). The two different areas were selected as regions of interest (ROIs) for future rsFC analysis. Compared with the same in RW subjects, in SD subjects, the right IPL showed decreased rsFC with the left PrC (BA7) and increased rsFC with the left fusiform gyrus (BA37) and the left cluster of middle temporal gyrus and inferior temporal gyrus (BA37). However, the left PrC/PCC did not show any connectivity differences. Compared with RW subjects, SD subjects showed lower ALFF area in the left IPL (BA39, 40). The left IPL, as an ROI, showed decreased rsFC with the right cluster of IPL and superior temporal gyrus (BA39, 40). ROC curve analysis showed that the area under the curve (AUC) value of the left IPL was 0.75, with a cutoff point of 0.834 (mean ALFF signal value). Further diagnostic analysis exhibited that the AUC alone discriminated SD status from RW status, with 75% sensitivity and 91.7% specificity. CONCLUSION: Long-term SD disturbed the spontaneous activity and connectivity pattern of DMN.

Nutlin-3-induced redistribution of chromatin-bound IFI16 in human hepatocellular carcinoma cells in vitro is associated with p53 activation.

AIM: Interferon-γ inducible protein 16 (IFI16), a DNA sensor for DNA double-strand break (DSB), is expressed in most human hepatocellular carcinoma cell (HCC) lines. In this study we investigated the re-localization of chromatin-bound IFI16 by Nutlin-3, a DNA damage agent, in HCC cells in vitro, and the potential mechanisms. METHODS: Human HCC SMMC-7721 (wild-type TP53), Huh-7 (mutant TP53), Hep3B (null TP53) and normal fetal liver L02 cell lines were examined. DSB damage in HCC cells was detected via γH2AX expression and foci formation assay. The expression of IFI16 and IFNB mRNA was measured using RT-PCR, and subcellular localization and expression of the IFI16 protein were detected using chromatin fractionation, Western blot analysis, and fluorescence microscopy. RESULTS: Treatment of SMMC-7721 cells with Nutlin-3 (10 µmol/L) or etoposide (40 µmol/L) induced significant DSB damage. In SMMC-7721 cells, Nutlin-3 significantly increased the expression levels of IFI16 and IFNB mRNA, and partially redistributed chromatin-bound IFI16 protein to the cytoplasm. These effects were blocked by pretreatment with pifithrin-α, a p53 inhibitor. Furthermore, Nutlin-3 did not induce ectopic expression of IFI16 protein in Huh-7 and Hep3B cells. Moreover, the association of IFI16 with chromatin and Nutlin-3-induced changes in localization were not detected in L02 cells. CONCLUSION: Nutlin-3 regulates the subcellular localization of IFI16 in HCC cells in vitro in a p53-dependent manner.

A high-fructose diet induces hippocampal insulin resistance and exacerbates memory deficits in male Sprague-Dawley rats.

The purpose of this study was to investigate the effects of a long-term high-fructose diet on the insulin-signaling pathway of the hippocampus. Sprague-Dawley rats were fed either on a control (0% fructose solution) or high-fructose diet (10% fructose solution). Food intake and body mass were measured regularly. Eight months later, peripheral insulin sensitivity, the activity of the hippocampal insulin pathway, and memory tasks were assessed. Compared to the control group, the high fructose group exhibited more weight gain, peripheral insulin resistance, metabolic disorders, and memory impairments. In addition, insulin signaling in the hippocampus was attenuated in the high fructose group. These results suggested that a high-fructose diet induced peripheral insulin resistance and an abnormal insulin-signaling pathway in the hippocampus which exacerbated memory deficits in the rats.