Alzheimer's disease-related presenilins are key to intestinal epithelial cell function and gut immune homoeostasis.

OBJECTIVE: Mutations in presenilin genes are the major cause of Alzheimer's disease. However, little is known about their expression and function in the gut. In this study, we identify the presenilins Psen1 and Psen2 as key molecules that maintain intestinal homoeostasis. DESIGN: Human inflammatory bowel disease (IBD) and control samples were analysed for Psen1 expression. Newly generated intestinal epithelium-specific Psen1-deficient, Psen2-deficient and inducible Psen1/Psen2 double-deficient mice were used to dissect the functional role of presenilins in intestinal homoeostasis. RESULTS: Psen1 expression was regulated in experimental gut inflammation and in patients with IBD. Induced deletion of Psen1 and Psen2 in mice caused rapid weight loss and spontaneous development of intestinal inflammation. Mice exhibited epithelial barrier disruption with bacterial translocation and deregulation of key pathways for nutrient uptake. Wasting disease was independent of gut inflammation and dysbiosis, as depletion of microbiota rescued Psen-deficient animals from spontaneous colitis development but not from weight loss. On a molecular level, intestinal epithelial cells lacking Psen showed impaired Notch signalling and dysregulated epithelial differentiation. CONCLUSION: Overall, our study provides evidence that Psen1 and Psen2 are important guardians of intestinal homoeostasis and future targets for barrier-promoting therapeutic strategies in IBD.

Stiffness promotes cell migration, invasion, and invadopodia in nasopharyngeal carcinoma by regulating the WT-CTTN level.

Matrix stiffness potently promotes the malignant phenotype in various biological contexts. Therefore, identification of gene expression to participate in mechanical force signals transduced into downstream biochemical signaling will contribute substantially to the advances in nasopharyngeal carcinoma (NPC) treatment. In the present study, we detected that cortactin (CTTN) played an indispensable role in matrix stiffness-induced cell migration, invasion, and invadopodia formation. Advances in cancer research have highlighted that dysregulated alternative splicing contributes to cancer progression as an oncogenic driver. However, whether WT-CTTN or splice variants (SV1-CTTN or SV2-CTTN) regulate matrix stiffness-induced malignant phenotype is largely unknown. We proved that alteration of WT-CTTN expression modulated matrix stiffness-induced cell migration, invasion, and invadopodia formation. Considering that splicing factors might drive cancer progression through positive feedback loops, we analyzed and showed how the splicing factor PTBP2 and TIA1 modulated the production of WT-CTTN. Moreover, we determined that high stiffness activated PTBP2 expression. Taken together, our findings showed that the PTBP2-WT-CTTN level increases upon stiffening and then promotes cell migration, invasion, and invadopodia formation in NPC.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation.

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Effects of Peripubertal Experiences on Competitive Behavior in Male Rats at Different Stages of Adulthood.

Past studies in animal models have extensively investigated the impact of early life experiences on behavioral development, yet relatively few have specifically examined the implications of peripubertal experiences on the evolution of competitive behavior across distinct stages of adulthood. In the current research, we probed potential differences in competitive behavior during emerging adulthood (3 months old) and middle adulthood (12 months old) in 81 Sprague-Dawley male rats exposed to three different peripubertal (postnatal Days 37-60) environments: an enriched environment (EE), a chronic unpredictable mild stress (CUMS) condition, and a control condition. Anxiety-like behavior served as a positive control in our study. Results revealed significant variations in competitive behavior among the groups during emerging adulthood. The EE group displayed the least anxiety and outperformed their peers in food-reward-oriented competition, whereas the CUMS group excelled in status-driven, agonistic competition. However, these behavioral differentiations gradually attenuated by middle adulthood, at which point the control group began to show an advantage. Our findings suggest that although peripubertal experiences significantly shape competitive behavior in the emerging adulthood stage, this effect diminishes over time and is nearly non-detectable during mid-adulthood, underscoring the fluidity of behavioral development and demonstrating that the effects of peripubertal experiences can be modulated by subsequent life experiences.

Two cases of complex traumatic aortic dissection combined with multiple organ injuries.

Traumatic aortic injury (TAI) is an acute, critical, and severe disease, and then combined with multiple organ damage, it is even more dangerous. TAI progresses very rapidly, with a pre-hospital mortality rate of 57% - 80%, and even when arriving at the hospital, more than one-third of the patients die within 4 h, and it is the 2nd leading cause of death in individuals aged 4 - 34 years. In addition, the incidence of TAI combined with injury was 81.4%. Therefore, early diagnosis, expeditious surgery, and timely and effective multidisciplinary cooperation are essential for successful rescue. The authors report 2 patients with acute traumatic aortic dissection combined with multiple organ injuries and treated with emergency endovascular surgery to discuss their clinical characteristics and treatment experience, and to provide experience in the diagnosis and treatment of such patients.

High Performance and Multifunction Moisture-Driven Yin-Yang-Interface Actuators Derived from Polyacrylamide Hydrogel.

High actuation performance of a moisture actuator highly depends on the presence of a large property difference between the two layers, which may cause interfacial delamination. Improving interfacial adhesion strength while increasing the difference between the layers is a challenge. In this study, a moisture-driven tri-layer actuator with a Yin-Yang-interface (YYI) design is investigated in which a moisture-responsive polyacrylamide (PAM) hydrogel layer (Yang) is combined with a moisture-inert polyethylene terephthalate (PET) layer (Yin) using an interfacial poly(2-ethylhexyl acrylate) (PEA) adhesion layer. Fast and large reversible bending, oscillation, and programmable morphing motions in response to moisture are realized. The response time, bending curvature, and response speed normalized by thickness are among the best compared with those of previously reported moisture-driven actuators. The excellent actuation performance of the actuator has potential multifunctional applications in moisture-controlled switches, mechanical grippers, and crawling and jumping motions. The Yin-Yang-interface design proposed in this work provides a new design strategy for high-performance intelligent materials and devices.

Protective effects of chlorogenic acid on inflammatory responses induced by Staphylococcus aureus and milk protein synthesis in bovine mammary epithelial cells.

Staphylococcus aureus (S. aureus) is a major mastitis-causing pathogen in dairy cows. Dairy cows with mastitis suffer from a decrease in milk yield and protein content. Chlorogenic acid (CGA) is a natural product with anti-inflammatory effects. In this study, we examined the function and mechanism of CGA with regard to its anti-inflammatory effects and evaluated its protective function in milk protein synthesis in bovine mammary epithelial cells (BMECs). BMECs were cultured with and without infection by S. aureus and CGA, and extracellular inflammatory cytokines and amino acids in the medium and milk proteins were determined by ELISA. The function of IL-10RA in anti-inflammatory processes and of SF-1 in milk protein synthesis was assessed by gene silencing. The activity of mTORC1, NF-κB, and STAT5 was examined by western blot. S. aureus caused intracellular infection and upregulated TNF-α, IL-1ß, IL-6, and IL-8, whereas uptake of amino acids and milk protein synthesis were suppressed. CGA mitigated the S. aureus-induced inflammatory response and milk protein synthesis in vitro and in vivo. CGA alleviated S. aureus-induced inhibition of mTORC1 and STAT5 and upregulated IL-10 and IL-10RA. In addition, SF-1 was predicted to be a transcription factor of the milk protein-encoding genes α-LA, ß-LG, and CSN2. S. aureus downregulated SF-1 and CGA reversed the decline in milk protein synthesis due to SF-1 knockdown. Thus, CGA mitigates the inflammatory response that is induced by S. aureus and protects the uptake of amino acids and milk protein synthesis in BMECs.

The Impact of CYP24A1 Polymorphisms on Hypertension Susceptibility.

BACKGROUND: Hypertension is one of the leading causes of human death and disability. CYP24A1 regulates vitamin D activity and is closely linked to hypertension. However, the relationship between CYP24A1polymorphisms and hypertension risk remains unclear. METHODS: This case-control study included 503 hypertensive patients and 498 healthy controls from the Chinese Han population. The genotypes of CYP24A1polymorphisms were detected using the Agena MassARRAY method. The association between genetic variations of CYP24A1and hypertension risk was evaluated with odds ratios (OR) and 95% confidence intervals (CI) in genetic models. RESULTS: We found that rs56229249 of CYP24A1significantlydecreased the hypertension risk in homozygote (OR 0.51, 95% CI 0.29-0.91, p = 0.022) and recessive models (OR 0.51, 95% CI 0.29-0.91, p = 0.023). Further stratification analyses indicated that hypertension risk is related to age and sex, rs2762934 polymorphism increases hypertension risk among younger subjects (<61 years), and rs1977297 influences the risk of hypertension among older subjects (≥61 years). In addition, rs2762940 is related to hypertension risk in men, and rs56229249 is a protective factor against hypertension in women. CONCLUSIONS: Our study suggests that genetic variations of the CYP24A1gene were significantly associated with susceptibility to hypertension in the Chinese population.

[Regulatory effect of Jinkui Shenqi Pills on the gene expression of the Nrf2 signaling pathway in cyclophosphamide-induced testis injury in mice].

OBJECTIVE: To investigate the protective effect of Jinkui Shenqi Pills (JSP) against cyclophosphamide-induced testis injury (TI) and its anti-oxidation mechanism in mice. METHODS: Thirty male mice were equally divided into a blank control, a TI model control and a JSP treatment group. The mice in the JSP treatment group were treated intragastrically with JSP and the blank controls with normal saline at 1.2 g/kg qd for 7 days, and then the animals in both the TI model control and JSP treatment groups were injected intraperitoneally with cyclophosphamide at 50 mg/kg, once a week, for 35 days, to induce testis injury. After modeling, all the mice were weighed and sacrificed, followed by detection of the serum T content, measurement of the testis weight, examination of semen parameters in the caudad epididymis, and determination of the levels of super oxide dismutase (SOD) and malondialdehyde (MDA) in the testis tissue and the expressions of relevant genes by qRT-PCR. RESULTS: The mice of the TI model control group, compared with the blank controls, showed significant decreases in the body weight (ï¼»34.63 ± 1.92ï¼½ vs ï¼»48.32 ± 1.64ï¼½ g, P<0.05), testis weight (ï¼»80.00 ± 3.90ï¼½ vs ï¼»140.00 ± 6.10ï¼½ mg, P<0.05), testicular organ coefficient (ï¼»0.22 ± 0.01ï¼½ vs ï¼»0.31 ±0.03ï¼½%, P<0.05), sperm motility (ï¼»48.66 ± 8.08ï¼½% vs ï¼»89.33 ± 4.04ï¼½%, P<0.05), sperm concentration (ï¼»28.42 ± 5.26ï¼½ vs ï¼»77.67 ± 8.73ï¼½ ×106/ml, P<0.05), and levels of serum T (ï¼»8.75 ± 0.96ï¼½ vs ï¼»21.75 ± 1.71ï¼½ pg/ml, P<0.05) and SOD (ï¼»140.82 ± 10.08ï¼½ vs ï¼»358.52 ± 40.41ï¼½ U/mg prot, P<0.05), but remarkable increases in the sperm deformity rate (ï¼»37.33 ± 2.08ï¼½ vs ï¼»15.33±1.53ï¼½%, P<0.05) and MDA level (ï¼»54.89±6.09ï¼½ vs ï¼»30.21±2.17ï¼½ nmol/ng prot, P<0.05). The mice of the JSP treatment group, in comparison with the TI model controls, exhibited markedly increased body weight (ï¼»39.80±2.89ï¼½ vs ï¼»34.63±1.92ï¼½g, P<0.05), testis weight (ï¼»130.00 ± 11.00ï¼½ vs ï¼»80.00 ± 3.90ï¼½ mg, P<0.05), testicular organ coefficient (ï¼»0.28 ± 0.01ï¼½ vs ï¼»0.22 ± 0.01ï¼½%, P<0.05), sperm motility (ï¼»76.00 ± 5.29ï¼½% vs ï¼»48.66 ± 8.08ï¼½%, P<0.05), sperm concentration (ï¼»56.08 ± 4.29ï¼½ vs ï¼»28.42 ± 5.26ï¼½ ×106/ml, P<0.05), and levels of serum T (ï¼»15.50 ± 1.29ï¼½ vs ï¼»8.75 ± 0.96ï¼½ pg/ml, P<0.05) and SOD (ï¼»206.59 ± 16.38ï¼½ vs ï¼»140.82 ± 10.08ï¼½ U/mg prot, P<0.05), but decreased sperm deformity rate (ï¼»25.01 ± 2.99ï¼½% vs ï¼»37.33 ± 2.08ï¼½%, P<0.05) and MDA level (ï¼»35.84 ± 3.61ï¼½ vs ï¼»54.89 ± 6.09ï¼½ nmol/ng prot, P<0.05). The mRNA expressions of NOQ-1, Nrf2 and HO-1 in the testis tissue were significantly lower and that of Caspase-3 remarkably higher in the TI model control than in the blank control group (P<0.05), while those of Nrf2 and HO-1 significantly higher and that of Caspase-3 markedly lower in the JSP treatment group than in the TI model controls (P<0.05). Histopathological images displayed reduced layers of spermatogenic cells in the seminiferous tubules, complete exfoliation of the spermatogenic cells in some of the tubules and decreased number of sperm cells in the TI model controls, which were all found normal in the JSP treatment group. CONCLUSIONS: Jinkui Shenqi Pills can effectively inhibit cyclophosphamide-induced testis injury, which may be related to its effect of regulating the gene expression of the Nrf2 signaling pathway and enhancing the activity of antioxidant enzymes.

Correlation Between Dual-Energy Computed Tomography Single Scan and Computed Tomography Perfusion for Pancreatic Cancer Patients: Initial Experience.

OBJECTIVE: The objective of this study was to evaluate the role and limit of iodine maps by dual-energy computed tomography (CT) single scan for pancreatic cancer. METHODS: Thirty patients with suspected solitary pancreatic cancer were enrolled in this study and underwent CT perfusion and iodine maps. The parameters of pancreatic cancer and normal pancreatic tissue were calculated. Pearson correlation and paired t test were used for evaluating 2 techniques. RESULTS: Iodine concentration had a moderate positive correlation with blood flow or blood volume (P < 0.05 for both). All values of iodine concentration and blood flow, iodine concentration, and blood volume had significant positive correlations (P < 0.001 for both). The mean effective dose for CT perfusion and iodine maps had significant difference (8.61 ± 0.00 mSv vs 1.13 ± 0.14 mSv, P < 0.001). CONCLUSIONS: Iodine maps had the potential to replace routine CT perfusion for pancreatic cancer with low radiation dose.

Leachability of heavy metals in loess-amended dredged sediment from Northwest of China.

Considerable studies have been done on heavy metal removing from aqueous solutions using loess. However, application of loess to heavy metal contaminated sediment is limited. The present study was to determine the effectiveness of loess to immobilize Cu, Zn, Cd and Pb in sediment. The loess was incubated with 10 kg wet sediment in doses of 0, 0.5, 1, 2, 5, 10 and 20 kg for 70 d and then subjected to the toxicity characteristic leaching procedure (TCLP). The possible mechanisms for heavy metal immobilization were illustrated using X-ray diffraction and scanning electron microscope. Results from TCLP confirmed loess reduced leaching rate of Cu and Zn achieving up to 42.4% and 17.6% reductions, respectively, when compared with untreated sediment. The loess could significantly immobilize Cu and Zn in sediment, and the optimum dose of loess in 10 kg wet sediment was 5 kg. However, loess was inefficient for Cd and Pb immobilization. Correlation analysis showed that TCLP extraction method could be used to predict the toxicity of Cu, Zn, Cd and Pb in the loess-amended sediment. The pH, EC, OM and CaCO3 of the loess-amended sediment played predominant roles in the TCLP leaching test.

Electronic Properties and Electroluminescent OLED Performance of Panchromatic Emissive N-Aryl-2,3-naphthalimides.

This report investigates the excited-state properties of a series of N-aryl-2,3-naphthalimides along with their fabrication into OLEDs and electroluminescence measurements. The N-aryl-2,3-NIs substituted specifically with chloro, fluoro, and methoxy substituents were chosen because of their unique propensity to display two emission bands or panchromatic fluorescence. Using the Lippert-Mataga analysis along with TD-DFT calculations, the excited states were determined to be n,π* and π,π*. The TD-DFT calculations on the geometries of the excited states indicate that the excited state shows a planar structure. The origin of both the short wavelength (SW) and long wavelength (LW) emission were correlated to specific geometries such that the SW emission originates from an "angled" structure in the excited state, and LW emission originates from an excited state of coplanar structure. All of the dyes investigated readily formed good films under ultrahigh vacuum deposition. The molecular energy levels of these compounds (HOMO and LUMO) were measured with cyclic voltammetry. Band gaps were also measured in both electrochemical and optical methods and indicate that the HOMOs of these fluorophores matched well with the anode (ITO work function), and their LUMOs matched well with the cathode (LiF/Al). To compare photoluminescence of the four dyes with their potential electroluminescence, three OLED devices were designed and fabricated. The electroluminescent spectra of these devices indicate that the panchromatic fluorescence, observed in solution, shifts toward the red in the solid-state. A plausible explanation appears to stem from an inability to inject electrons to the higher LUMO+1 orbitals; a process observed in the solution phase. Hence, the short wavelength fluorescence peak, a key component to panchromatic luminescence disappears in the OLED device. The observed EL spectrum from these smaller heteroatomic architectures is on par if not more broadly emissive than rubrene (5,6,11,12-tetraphenyltetracene), a red-colored C42H28 polycyclic aromatic hydrocarbon, that displays an orange-color EL.

A quantitative transcriptomic analysis of the physiological significance of mTOR signaling in goat fetal fibroblasts.

BACKGROUND: Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that is a central regulator of cell growth and metabolism. CCI-779 is a specific inhibitor of the mTORC1 signaling pathway. RESULTS: We performed comparative transcriptome profiling on Inner Mongolia Cashmere goat fetal fibroblasts (GFbs) that were treated with CCI-779 and untreated cells. A total of 365 differentially expressed genes (DEGs) appeared between untreated and CCI-779-treated GFbs, with an FDR ≤0.001 and fold-change ≥2. These 365 DEGs were associated with mTOR signaling; 144 were upregulated in CCI-779-treated cells, and 221 were downregulated. Additionally, 300 genes were annotated with 43 Gene Ontology (GO) terms, and 293 genes were annotated with 194 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Three RNA polymerase II and polymerase III subunits, 3 transcription factors, and 5 kinases in mTOR signaling were differentially expressed in CCI-779-treated GFbs. Further 6 DEGs were related to amino acid metabolism, 11 mediated lipid metabolism, 11 participated in carbohydrate metabolism, and 5 were involved in single-nucleotide metabolism. Based on our quantitative transcriptomic analysis, 40 significant DEGs with important function related to metabolism, RNA polymerase, transcription factors and mTOR signaling were selected for qPCR analysis, and the quantitative results between the two analysis methods were concordant. The qPCR data confirmed the differential expression in the RNA-Seq experiments. To validate the translational significance of the findings in certain differentially expressed genes, S6K1 and VEGF were detected by western blot, and these two proteins showed a differential expression between non-treated and treated with CCI-779 groups, which were consistent with mRNA abundance. The data showed a preliminary significance of the findings in the protein levels. CONCLUSIONS: CCI-779 induces transcriptomic changes, and mTOR signaling might have significant function in the activation of RNA polymerase and certain transcription factors and in the metabolism of amino acids, lipids, carbohydrates, and single nucleotides in GFbs. These data filled the vacancy in the systematical profiling of mTOR signaling on Cashmere goat fetal fibroblasts.

Long non-coding RNA ROR promotes proliferation, migration and chemoresistance of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies of the head and neck. It arises from the nasopharynx epithelium and is associated with high morbidity and mortality. Long non-coding RNA (lncRNA) have been reported to regulate gene interaction and play critical roles in carcinogenesis and progression. LncRNA-ROR, a recently identified lncRNA, has been shown to be involved in initiation, progression and metastasis of several tumors, including hepatocellular carcinoma, breast cancer and glioma. However, whether lncRNA-ROR is associated with the progression of NPC remains unknown. Resistance to radiotherapy and chemotherapy is the primary cause of NPC patients' death. In this study, we found that lncRNA-ROR was significantly upregulated in NPC tissues compared with normal tissues. Next, our study proved that lncRNA-ROR was highly associated with the proliferation, metastasis and apoptosis of NPC. The enrichment of lncRNA-ROR played a critucal functional role in chemoresistance. The mechanism by which NPC resists chemotherapy might be that lncRNA-ROR suppress p53 signal pathway. Taken together, these data suggested that lncRNA-ROR played an important role in the progression of NPC; thereby it might become a therapeutic target and reduce chemoresistance for NPC.

Elevated expression of CD93 promotes angiogenesis and tumor growth in nasopharyngeal carcinoma.

CD93, also known as the complement component C1q receptor (C1qRp), has been reported to promote the progression of some cancer types. However, the expression and physiological significance of CD93 in nasopharyngeal carcinoma (NPC) remain largely elusive. In this study, we first examined the expression of CD93 in NPC and experimentally manipulated its expression. We observed that vascular CD93 expression is elevated in NPC and is correlated with T classification, N classification, distant metastasis, clinical stage and poor prognosis (all P < 0.05). In addition, overexpression of CD93 promoted angiogenesis in vitro. What's more, we found that CD93 was highly expressed in NPC tissues and cells, and the regulation of CD93 on cell proliferation was determined by cell counting kit (CCK)-8 assay and cell cycle analyses. Our findings provide unique insight into the pathogenesis of NPC and underscore the need to explore novel therapeutic targets such as CD93 to improve NPC treatment.

Overexpression of IGFBP3 is associated with poor prognosis and tumor metastasis in nasopharyngeal carcinoma.

Insulin-like growth factor-binding protein-3 (IGFBP3) is an N-linked glycosylated, phosphorylated protein, which has been reported to regulate cancer progression and metastasis. However, the role of IGFBP3 in tumor metastasis remains under debate. Nasopharyngeal carcinoma (NPC) is a highly metastatic head and neck cancer. And it fails to achieve the desired therapeutic efficacy in patients with metastasis, while the role of IGFBP3 in NPC is still unclear. In this study, we first used immunohistochemistry to explore the expression of IGFBP3 in NPC tissues. We found that IGFBP3 was significantly elevated in NPC and its expression level was correlated with N classification, distant metastasis, and TNM clinical stage (all P < 0.05). Patients with high expression of IGFBP3 had poorer survival rate (P < 0.05). In addition, we found that downregulation of IGFBP3 inhibited cell migration and adhesion by Transwell migration assay, wounding healing assay, and cell adhesion assays in vitro. Besides, NPC cells stimulated with recombinant IGFBP3 accelerated migration and adhesion. These data suggest overexpression of IGFBP3 promotes tumor metastasis in NPC, which makes it a potential therapeutic target.

Rapamycin Inhibits Expression of Elongation of Very-long-chain Fatty Acids 1 and Synthesis of Docosahexaenoic Acid in Bovine Mammary Epithelial Cells.

Mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth and metabolism and is sufficient to induce specific metabolic processes, including de novo lipid biosynthesis. Elongation of very-long-chain fatty acids 1 (ELOVL1) is a ubiquitously expressed gene and the product of which was thought to be associated with elongation of carbon (C) chain in fatty acids. In the present study, we examined the effects of rapamycin, a specific inhibitor of mTORC1, on ELOVL1 expression and docosahexaenoic acid (DHA, C22:6 n-3) synthesis in bovine mammary epithelial cells (BMECs). We found that rapamycin decreased the relative abundance of ELOVL1 mRNA, ELOVL1 expression and the level of DHA in a time-dependent manner. These data indicate that ELOVL1 expression and DHA synthesis are regulated by mTORC1 in BMECs.

HCV infection selectively impairs type I but not type III IFN signaling.

A stable and persistent Hepatitis C virus (HCV) replication cell culture model was developed to examine clearance of viral replication during long-term treatment using interferon-α (IFN-α), IFN-λ, and ribavirin (RBV). Persistently HCV-infected cell culture exhibited an impaired antiviral response to IFN-α+RBV combination treatment, whereas IFN-λ treatment produced a strong and sustained antiviral response that cleared HCV replication. HCV replication in persistently infected cells induced chronic endoplasmic reticulum (ER) stress and an autophagy response that selectively down-regulated the functional IFN-α receptor-1 chain of type I, but not type II (IFN-γ) or type III (IFN-λ) IFN receptors. Down-regulation of IFN-α receptor-1 resulted in defective JAK-STAT signaling, impaired STAT phosphorylation, and impaired nuclear translocation of STAT. Furthermore, HCV replication impaired RBV uptake, because of reduced expression of the nucleoside transporters ENT1 and CNT1. Silencing ER stress and the autophagy response using chemical inhibitors or siRNA additively inhibited HCV replication and induced viral clearance by the IFN-α+RBV combination treatment. These results indicate that HCV induces ER stress and that the autophagy response selectively impairs type I (but not type III) IFN signaling, which explains why IFN-λ (but not IFN-α) produced a sustained antiviral response against HCV. The results also indicate that inhibition of ER stress and of the autophagy response overcomes IFN-α+RBV resistance mechanisms associated with HCV infection.

Inhibition of Mammalian Target of Rapamycin Complex 1 (mTORC1) Downregulates ELOVL1 Gene Expression and Fatty Acid Synthesis in Goat Fetal Fibroblasts.

Elongation of very-long-chain fatty acids 1 (ELOVL1) is a ubiquitously expressed gene that belongs to the ELOVL family and regulates the synthesis of very-long-chain fatty acids (VLCFAs) and sphingolipids, from yeast to mammals. Mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of cell metabolism and is associated with fatty acids synthesis. In this study, we cloned the cDNA that encodes Cashmere goat (Capra hircus) ELOVL1 (GenBank Accession number KF549985) and investigated its expression in 10 tissues. ELOVL1 cDNA was 840 bp, encoding a deduced protein of 279 amino acids, and ELOVL1 mRNA was expressed in a wide range of tissues. Inhibition of mTORC1 by rapamycin decreased ELOVL1 expression and fatty acids synthesis in Cashmere goat fetal fibroblasts. These data show that ELOVL1 expression is regulated by mTORC1 and that mTORC1 has significant function in fatty acids synthesis in Cashmere goat.

Impaired autophagy response in human hepatocellular carcinoma.

BACKGROUND: Autophagy is a cellular lysosomal degradation mechanism that has been implicated in chronic liver diseases and hepatocellular carcinoma (HCC). Association of autophagy defect with the development of human HCC has been shown in transgenic mouse model. AIM: We performed this study to verify whether a defect in autophagy would play a role in human hepatocellular carcinoma (HCC). METHODS: Archival tissue sections of 20 patients with HCC with or without hepatitis C virus (HCV) infection were studied. All slides were immunostained using monoclonal antibodies to p62 and glypican-3 with appropriate positive and negative controls. The expression of p62 and glycican-3 in the HCC and the surrounding non-tumor was semiquantitated. The cytoplasmic staining was graded as negative, weak or strong. RESULTS: Positive p62 staining was found in 20 out of 20 (100%) HCCs and negative staining was observed in 20 out of 20 non-tumor areas and cirrhotic nodules. Positive glypican-3 staining was found in 70% of HCCs and negative staining was seen in all non-tumor areas. An autophagy defect leading to increased expression of p62 and glypican-3 was also seen in the HCC cell line (Huh-7.5), but not in the primary human hepatocytes. Activation of cellular autophagy in Huh-7.5 cells efficiently cleared p62 and glypican-3 expression and inhibition of autophagy induced the expression of p62 and glypican-3. CONCLUSIONS: This study shows that p62 is increased in HCC compared to the surrounding non-tumorous liver tissue suggesting that human HCCs are autophagy defective. We provide further evidence that glypican-3 expression in HCC may also be related to defective autophagy. Our study indicates that p62 immunostain may represent a novel marker for HCC.