iASPP regulates neurite development by interacting with Spectrin proteins.

Introduction: Since its discovery in 1999, a substantial body of research has shown that iASPP is highly expressed in various kinds of tumors, interacts with p53, and promotes cancer cell survival by antagonizing the apoptotic activity of p53. However, its role in neurodevelopment is still unknown. Methods: We studied the role of iASPP in neuronal differentiation through different neuronal differentiation cellular models, combined with immunohistochemistry, RNA interference and gene overexpression, and studied the molecular mechanism involved in the regulation of neuronal development by iASPP through coimmunoprecipitation coupled with mass spectrometry (CoIP-MS) and coimmunoprecipitation (CoIP). Results: In this study, we found that the expression of iASPP gradually decreased during neuronal development. iASPP silencing promotes neuronal differentiation, while its overexpression inhibited neurite differentiation in a variety of neuronal differentiation cellular models. iASPP associated with the cytoskeleton-related protein Sptan1 and dephosphorylated the serine residues in the last spectrin repeat domain of Sptan1 by recruiting PP1. The non-phosphorylated and phosphomimetic mutant form of Sptbn1 inhibited and promoted neuronal cell development respectively. Conclusion: Overall, we demonstrate that iASPP suppressed neurite development by inhibiting phosphorylation of Sptbn1.

Mothers with hypertensive disorders of pregnancy increased risk of periventricular leukomalacia in extremely preterm or extremely low birth weight infants: A propensity score analysis.

Background: At present, the conclusions about the impact of hypertensive disorders of pregnancy (HDP) on the clinical outcomes of preterm infants are inconsistent. This study used the propensity score matching (PSM) analysis to evaluate the effect of HDP on clinical outcomes of extremely preterm or extremely low birth weight (EP/ELBW) infants. Methods: Retrospective analysis was performed on the EP/ELBW infants discharged from 26 tertiary neonatal intensive care units or died during hospitalization from 2008 to 2017, who were divided into HDP group and non-HDP group. The six covariates including sex, gestational age, birth weight, twin or multiple pregnancy, antenatal steroids administration, and conception method were matched through the PSM method at a ratio of 1:1. The survival rate at discharge and the major clinical complications were compared between the two groups. Results: After matching the six covariates, compared with the non-HDP group, there was no significant difference in the survival rate at discharge (64 vs. 63.2%, p > 0.05), the incidence of bronchopulmonary dysplasia (BPD) or moderate to severe BPD in the HDP group (58.3 vs. 54.9%, p > 0.05; 5.2 vs. 6.2%, p > 0.05). The incidence of periventricular leukomalacia (PVL) in the HDP group was significantly increased (5.7 vs. 1.9%, p < 0.05). Conclusions: HDP increased the risk of PVL in EP/ELBW infants, but had no significant effect on the survival rate at discharge, or the occurrence of other complications.

[Sex differences in clinical outcomes of extremely preterm infants/extremely low birth weight infants: a propensity score matching study]. / è¶ æ—©äº§å„¿/è¶ ä½Žå‡ºç”Ÿä½“é‡å„¿ä¸´åºŠç»“å±€çš„æ€§åˆ«å·®å¼‚ï¼šä¸€é¡¹å€¾å‘æ€§è¯„åˆ†åŒ¹é ç ”ç©¶.

OBJECTIVES: To study the effect of sex on the clinical outcome of extremely preterm infants (EPIs)/extremely low birth weight infants (ELBWIs) by propensity score matching. METHODS: A retrospective analysis was performed for the medical data of 731 EPIs or ELBWIs who were admitted from January 1, 2011 to December 31, 2020. These infants were divided into two groups: male and female. A propensity score matching analysis was performed at a ratio of 1:1. The matching variables included gestational age, birth weight, percentage of withdrawal from active treatment, percentage of small-for-gestational-age infant, percentage of use of pulmonary surfactant, percentage of 1-minute Apgar score ≤3, percentage of mechanical ventilation, duration of mechanical ventilation, percentage of antenatal use of inadequate glucocorticoids, and percentage of hypertensive disorders in pregnancy. The two groups were compared in the incidence rate of main complications during hospitalization and the rate of survival at discharge. RESULTS: Before matching, compared with the female group, the male group had significantly higher incidence rates of neonatal respiratory distress syndrome, bronchopulmonary dysplasia (BPD), severe intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, and patent ductus arteriosus (P<0.05), while after matching, the male group only had a significantly higher incidence rate of BPD than the female group (P<0.05). There was no significant difference in the rate of survival at discharge between the two groups before and after matching (P>0.05). CONCLUSIONS: Male EPIs/ELBWIs have a higher risk of BPD than female EPIs/ELBWIs, but male and female EPIs/ELBWIs tend to have similar outcomes.

Increased Risk for Respiratory Complications in Male Extremely Preterm Infants: A Propensity Score Matching Study.

Background: Many factors can affect the clinical outcome of extremely premature infants (EPIs), but the effect of sex is paradoxical. This study used propensity score matching to adjust baseline information to reassess the clinical outcome of EPIs based on sex. Methods: A retrospective analysis was performed on EPIs admitted in the Department of Neonatology of the Third Affiliated Hospital of Guangzhou Medical University from 2011 to 2020. A propensity score matching (PSM) analysis was used to adjust the confounding factors including gestational age, birth weight, 1-minute Apgar score ≤ 3, withholding or withdrawing life-sustaining treatment(WWLST), mechanical ventilation, duration of mechanical ventilation, the mother with advanced age (≥35 years old), complete-course antenatal steroid therapy and hypertensive disorders of pregnancy. The survival rate at discharge and the incidence of major complications were evaluated between the male and female groups. Results: A total of 439 EPIs were included, and 240 (54.7%) infants were males. After matching the nine confounding factors, 148 pairs of infants were finally enrolled. There was no significant difference in the survival rate at discharge, as well as the mortality of activating treatment or WWLST between the two groups (all P>0.05). However, the incidence of respiratory distress syndrome, bronchopulmonary dysplasia (BPD), and moderate to severe BPD in the male group was significantly increased (all P<0.01), especially at birth weight between 750 and 999 grams. Conclusions: The male EPIs have a higher risk of respiratory complications than females, particularly at 750 to 999 grams of birth weight.

Insight into the uptake, accumulation, and metabolism of the fungicide phenamacril in lettuce (Lactuca sativa L.) and radish (Raphanus sativus L.).

The fungal species Fusarium can cause devastating disease in agricultural crops. Phenamacril is an extremely specific cyanoacrylate fungicide and a strobilurine analog that has excellent efficacy against Fusarium. To date, information on the mechanisms involved in the uptake, accumulation, and metabolism of phenamacril in plants is scarce. In this study, lettuce and radish were chosen as model plants for a comparative analysis of the absorption, accumulation, and metabolic characteristics of phenamacril from a polluted environment. We determined the total amount of phenamacril in the plant-water system by measuring the concentrations in the solution and plant tissues at frequent intervals over the exposure period. Phenamacril was readily taken up by the plant roots with average root concentration factor ranges of 60.8-172.7 and 16.4-26.9 mL/g for lettuce and radish, respectively. However, it showed limited root-to-shoot translocation. The lettuce roots had a 2.8-12.4-fold higher phenamacril content than the shoots; whereas the radish plants demonstrated the opposite, with the shoots having 1.5 to 10.0 times more phenamacril than the roots. By the end of the exposure period, the mass losses from the plant-water systems reached 72.0% and 66.3% for phenamacril in lettuce and radish, respectively, suggesting evidence of phenamacril biotransformation. Further analysis confirmed that phenamacril was metabolized via hydroxylation, hydrolysis of esters, demethylation, and desaturation reactions, and formed multiple transformation products. This study furthers our understanding of the fate of phenamacril when it passes from the environment to plants and provides an important reference for its scientific use and risk assessment.

Apgar scores correlate with survival rate at discharge in extremely preterm infants with gestational age of 25-27 weeks

Low Apgar score is associated with increased risk of death in preterm or full-term infants. However, the use of Apgar score to assess extremely preterm (EP) infants is controversial. In this study, we characterized the distribution of Apgar scores in EP infants with gestational age between 25 and 27 weeks, and investigated the association of Apgar score with survival rate at discharge by analyzing the clinical data of the EP infants discharged between January 2008 and December 2017 from 26 neonatal intensive care units in Guangdong Province, China. A total of 1567 infants with gestational age of 26.84±0.79 weeks and birth weight of 951±169 grams were involved in our study. The Apgar score increased with gestational age from 25 to 27 weeks and with time from birth from 1 to 10 min. The survival rate increased with a higher Apgar score, but no significant difference was found for 1-min Apgar score and the survival rate between infants with 25 or 26 weeks of gestation or 5-min Apgar score in infants with 25 weeks of gestation. The Apgar score is associated with survival of EP infants.

Efficacy and safety of surfactant administration via thin catheter in preterm infants with neonatal respiratory distress syndrome: A systematic review and meta-analysis.

OBJECTIVE: The efficacy and safety of surfactant administration via thin catheter in preterm infants with neonatal respiratory distress syndrome (NRDS) was investigated. METHODS: PubMed, Embase, Cochrane Library, and Web of Science databases were searched to identify randomized controlled trials (RCTs) that comparing thin catheter technique with intubation for surfactant delivery in preterm infants with NRDS. RESULTS: Thirteen RCTs (1931 infants) were included in the meta-analysis. The use of thin catheter technique decreased the incidences of bronchopulmonary dysplasia (BPD), pneumothorax, and hemodynamically significant patent ductus arteriosus (hsPDA) (risk ratio [RR]: 0.59, 95% confidence interval [CI]: 0.46-0.75, p < .0001; RR: 0.60, 95% CI: 0.39-0.93, p = .02 and RR: 0.88, 95% CI: 0.78-1.00, p = .04, respectively). In addition, infants in the intervention group required less mechanical ventilation within 72 h of life or during hospitalization (RR: 0.60, 95% CI: 0.48-0.75, p < .00001 and RR: 0.64, 95% CI: 0.49-0.82, p = .0005, respectively) compared with infants in the control group. However, the rate of surfactant reflux was higher in the intervention group than that in the control group (RR: 2.12, 95% CI: 1.37-3.29, p = .0008). There were no significant differences in mortality and other outcomes between the two groups. CONCLUSION: The administration of surfactant via thin catheter could lower the requirement for mechanical ventilation, and decrease the incidence of BPD, pneumothorax, and hsPDA.

Analysis of the mTOR Interactome using SILAC technology revealed NICE-4 as a novel regulator of mTORC1 activity.

The evolutionarily conserved mechanistic target of rapamycin (mTOR) forms two functionally distinct complexes, -the mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2)-which differ in their subunit composition. Although the function of mTORC1 has been studied extensively, the interaction between mTORC1 and the ubiquitin-proteasome system (UPS) remains unclear. To facilitate a thorough understanding of the mechanismby which UPS regulates mTORC1 activity, steady isotope labeling with amino acids in cell culture (SILAC) technology was used to screen for potential mTORC1-interacting UPS members. Fourteen previously unknown proteins bound to mTOR in HEK293 cells with a SILAC ratio (heavy/light, H/L) above 2, five of which are components of the UPS. Subsequent immunoprecipitation analysis confirmed that ubiquitin-relevant protein 2-like (UBAP2L, also known as NICE-4) binds to both mTOR and Raptor, but not Rictor, suggesting that NICE-4 specifically interacts with mTORC1, but not mTORC2. Interestingly, NICE-4 is essential for basic mTORC1 activity in both HeLa cancer cells and HEK293 cells. In addition, NICE-4 depletion markedly suppressed proliferation of both HeLa and HEK293 cells as well as survival of HeLa cells. Collectively, these results revealed the identity of novel mTOR-interacting UPS proteins and established NICE-4 as a critical UPS member that maintains mTORC1 activity.

Umbilical Cord Blood-Derived Exosomes From Very Preterm Infants With Bronchopulmonary Dysplasia Impaired Endothelial Angiogenesis: Roles of Exosomal MicroRNAs.

Premature infants have a high risk of bronchopulmonary dysplasia (BPD), which is characterized by abnormal development of alveoli and pulmonary vessels. Exosomes and exosomal miRNAs (EXO-miRNAs) from bronchoalveolar lavage fluid are involved in the development of BPD and might serve as predictive biomarkers for BPD. However, the roles of exosomes and EXO-miRNAs from umbilical cord blood of BPD infants in regulating angiogenesis are yet to be elucidated. In this study, we showed that umbilical cord blood-derived exosomes from BPD infants impaired angiogenesis in vitro. Next-generation sequencing of EXO-miRNAs from preterm infants without (NBPD group) or with BPD (BPD group) uncovered a total of 418 differentially expressed (DE) EXO-miRNAs. These DE EXO-miRNAs were primarily enriched in cellular function-associated pathways including the PI3K/Akt and angiogenesis-related signaling pathways. Among those EXO-miRNAs which are associated with PI3K/Akt and angiogenesis-related signaling pathways, BPD reduced the expression of hsa-miR-103a-3p and hsa-miR-185-5p exhibiting the most significant reduction (14.3% and 23.1% of NBPD group, respectively); BPD increased hsa-miR-200a-3p expression by 2.64 folds of the NBPD group. Furthermore, overexpression of hsa-miR-103a-3p and hsa-miR-185-5p in normal human umbilical vein endothelial cells (HUVECs) significantly enhanced endothelial cell proliferation, tube formation, and cell migration, whereas overexpressing hsa-miR-200a-3p inhibited these cellular responses. This study demonstrates that exosomes derived from umbilical cord blood of BPD infants impair angiogenesis, possibly via DE EXO-miRNAs, which might contribute to the development of BPD.

Occurrence and dietary risk assessment of 37 pesticides in wheat fields in the suburbs of Beijing, China.

The co-occurrence of multiple pesticides in wheat fields adversely affects human health and the environment. Herein, 206 pairs of wheat and soil samples were collected from wheat fields in Beijing, China from 2018 to 2020. One or multiple pesticide residues were detected, and carbendazim (maximum: 38511.5 µg/kg) and tebuconazole (maximum: 45.4 µg/kg) had heavy occurrence in the wheat samples. Carbendazim, triazoles, and neonicotinoids were frequently detected in the soil samples. HCHs and DDTs were detected, with p,p'-DDE in 100.0% of the soil samples at a maximum concentration of 546.0 µg/kg in 2020. Concentrations of carbendazim, tebuconazole, hexaconazole, and cyhalothrin in the paired soil and wheat samples exhibited significant positive correlations. Pesticides that exceeded the maximum residue limits do not pose non-carcinogenic risks, with one exception. The results provide important references towards risk monitoring and control in wheat fields, as well as facilitating the scientific and reasonable use of these pesticides.

DEPTOR Deficiency-Mediated mTORc1 Hyperactivation in Vascular Endothelial Cells Promotes Angiogenesis.

BACKGROUND/AIMS: The mechanistic target of rapamycin (mTOR) signaling pathway is essential for angiogenesis and embryonic development. DEP domain-containing mTOR-interacting protein (DEPTOR) is an mTOR binding protein that functions to inhibit the mTOR pathway In vitro experiments suggest that DEPTOR is crucial for vascular endothelial cell (EC) activation and angiogenic responses. However, knowledge of the effects of DEPTOR on angiogenesis in vivo is limited. This study aimed to determine the role of DEPTOR in tissue angiogenesis and to elucidate the molecular mechanisms. METHODS: Cre/loxP conditional gene knockout strategy was used to delete the Deptor gene in mouse vascular ECs. The expression or distribution of cluster of differentiation 31 (CD31), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1 alpha (HIF-1α) were detected by immunohistochemical staining or western blot. Tube formation assay was used to measure angiogenesis in vitro. RESULTS: Deptor knockdown led to increased expression of CD31, VEGF and HIF-1α in heart, liver, kidney and aorta. After treatment with rapamycin, their expression was significantly down regulated. In vitro, human umbilical vein endothelial cells (HUVECs) were transfected with DEPTOR-specific small interfering RNA (siRNA), which resulted in a significant increase in endothelial tube formation and migration rates. In contrast, DEPTOR overexpression markedly reduced the expression of CD31, VEGF and HIF-1α. CONCLUSIONS: Our findings demonstrated that deletion of the Deptor gene in vascular ECs resulted in upregulated expression of CD31 and HIF-1α, and further stimulated the expression of VEGF which promoted angiogenesis, indicating that disruption of normal angiogenic pathways may occur through hyperactivation of the mTORC1/HIF-1α/VEGF signaling pathway.

The association between surfactant protein B gene variation and bronchopulmonary dysplasia in Chinese premature newborns.

OBJECTIVE: This study aimed to correlate the pulmonary surfactant B (SP-B) gene variation with bronchopulmonary dysplasia (BPD) in ethnic Han, Chinese, premature newborns. METHOD: 47 newborns with BPD and 55 controls without BPD were included. Genomic DNA was extracted from cord or artery blood. Genotyping for the SP-B gene was performed by polymerase chain reaction or gene sequencing, and the clinical characteristics were also analyzed. RESULTS: Two types of SP-B gene variations in Exon 2 or Exon 5 were discovered, including V1 (Exon 2: c.[5A > C] + [5A > C] or c.[5A > C] + [=]) and V2 (Exon 5: c.[428C > T] + [428C > T] or c.[428C > T] + [=]). In the BPD group, there were 33 newborns with gene variations, of which type V1 and V2 accounted for 18 and 15 respectively. In the control group, there were 19 newborns with gene variations, of which type V1 and V2 accounted for 7 and 12 respectively. There was a significant difference between the two groups in type V1 variation (X2=8.956, P < 0.05), and V1 variation was more likely associated with BPD occurrence. Logistic regression analysis showed that gene variation, premature rupture of membranes, birth weight, and the duration of mechanical ventilation were associated with BPD development. Among them, gene variation and premature rupture of the membranes were risk factors for BPD development. CONCLUSIONS: The exon 2 or 5 of SP-B gene variations were associated with the BPD in Chinese premature newborns, and the type V1: Exon 2: c.[5A > C] + [5A > C] or c.[5A > C] + [=] was a risk factor for the development of BPD.

Different concentrations of docosahexanoic acid supplement during lactation result in different outcomes in preterm Sprague-Dawley rats.

PROPOSE: In this study, we evaluated the effects of different concentrations of docosahexanoic acid (DHA) supplement on preterm Sprague-Dawley rat pups, and in parallel, measured the phosphorylation activity of the mTOR pathway in the hippocampal CA1 area. METHODS: Preterm Sprague-Dawley rat pups were randomly assigned to experimental groups which included; a sufficient DHA group (100 mg/kg/day); an enriched DHA group (300 mg/kg/day); an excess DHA group (800 mg/kg/day); and a deficient DHA group (normal saline gavage 0.1 ml/10 g). Body weight (g) was measured at days 1/7/14/21/28/42, respectively. Spatial learning and memory were also tested using the Morris water maze at week 6 (day 42). Finally, activation of the mTOR signaling pathway in hippocampal CA1 area were evaluated by western blotting. RESULTS: Postnatal sufficient/enriched docosahexanoic acid supplement ameliorated body weight restriction, spatial learning and memory restriction, and decreased phosphorylation of AKT, mTOR, P70S6K1, and 4EBP1 in hippocampal CA1 area. Furthermore, excess docosahexanoic acid supplement impeded weight gain and spatial learning and memory, perturbed serum unsaturated fatty acid, and downregulated phosphorylation of AKT, mTOR, P70S6K1, and 4EBP1 in hippocampal CA1 area. CONCLUSION: Postnatal sufficient/enriched DHA supplement ameliorated growth and spatial learning and memory impairment and upregulated the mTOR pathway in preterm pups, although excessive DHA supplement did not have any beneficial effects.

Osteoblasts support megakaryopoiesis through production of interleukin-9.

Severe thrombocytopenia is a significant challenge in patients undergoing myelosuppressive chemotherapy for malignancies. Understanding the biology of platelet-producing megakaryocytes development in the bone marrow microenvironment may facilitate the development of novel therapies to stimulate platelet production and prevent thrombocytopenia. We report here that osteoblasts supported megakaryopoiesis by secreting interleukin-9 (IL-9), which stimulated IL-9 receptor (IL-9R)/Stat3 signaling in promoting megakaryopoiesis. IL-9 production in osteoblasts was negatively regulated by the mechanistic target of rapamycin complex 1 (mTORC1) signaling in a NF-κB-dependent manner. Constitutive activation of mTORC1 inhibited IL-9 production in osteoblasts and suppressed megakaryocytic cells expansion, whereas mTORC1 inactivation increased IL-9 production and enhanced megakaryocyte and platelet numbers in mice. In mouse models, we showed that IL-9 administration stimulated megakaryopoiesis, whereas neutralizing endogenous IL-9 or IL-9R depletion inhibited the process. Importantly, we found that low doses of IL-9 efficiently prevented chemotherapy-induced thrombocytopenia (CIT) and accelerated platelet recovery after CIT. These data indicate that IL-9 is an essential regulator of megakaryopoiesis and a promising therapeutic agent for treatment of thrombocytopenia such as CIT.

Different functions of DEPTOR in modulating sensitivity to chemotherapy for esophageal squamous cell carcinoma.

There have been paradoxical findings regarding the expression of DEP domain-containing mTOR-interacting protein (DEPTOR) and its role in predicting prognosis in esophageal squamous cell carcinoma (ESCC). Here we show that DEPTOR expression was significantly increased in tumor tissues and predicted good survival in early stage ESCC patients but not in advanced stage patients. In vitro，our studies showed that ESCC cell lines could be classified into relatively high and low DEPTOR-expressing subgroups according to esophageal squamous epithelial cell line Het-1A.In our study, different levels of DEPTOR expression absolutely determined the response to chemotherapy. In relatively low-expressing cell lines, DEPTOR increased chemotherapy sensitivity via deactivation of the AKT pathway. In relatively high-expressing cell lines, DEPTOR increased cell survival and chemoresistance by strong feedback activation of the IRS1-PI3K-AKT-survivin pathway that occurred after downregulation of ribosomal protein S6 kinase (S6K). Collectively, our findings highlight the dichotomous nature of DEPTOR functions in modulating chemotherapy sensitivity in different ESCC cells.

Osteoblasts secrete Cxcl9 to regulate angiogenesis in bone.

Communication between osteoblasts and endothelial cells (ECs) is essential for bone turnover, but the molecular mechanisms of such communication are not well defined. Here we identify Cxcl9 as an angiostatic factor secreted by osteoblasts in the bone marrow microenvironment. We show that Cxcl9 produced by osteoblasts interacts with vascular endothelial growth factor and prevents its binding to ECs and osteoblasts, thus abrogating angiogenesis and osteogenesis both in mouse bone and in vitro. The mechanistic target of rapamycin complex 1 activates Cxcl9 expression by transcriptional upregulation of STAT1 and increases binding of STAT1 to the Cxcl9 promoter in osteoblasts. These findings reveal the essential role of osteoblast-produced Cxcl9 in angiogenesis and osteogenesis in bone, and Cxcl9 can be targeted to elevate bone angiogenesis and prevent bone loss-related diseases.

mTOR Overactivation in Mesenchymal cells Aggravates CCl4- Induced liver Fibrosis.

Hepatic stellate cells are of mesenchymal cell type located in the space of Disse. Upon liver injury, HSCs transactivate into myofibroblasts with increase in expression of fibrillar collagen, especially collagen I and III, leading to liver fibrosis. Previous studies have shown mTOR signaling is activated during liver fibrosis. However, there is no direct evidence in vivo. The aim of this study is to examine the effects of conditional deletion of TSC1 in mesenchymal on pathogenesis of liver fibrosis. Crossing mice bearing the floxed TSC1 gene with mice harboring Col1α2-Cre-ER(T) successfully generated progeny with a conditional knockout of TSC1 (TSC1 CKO) in collagen I expressing mesenchymal cells. TSC1 CKO and WT mice were subjected to CCl4, oil or CCl4+ rapamycin treatment for 8 weeks. TSC1 CKO mice developed pronounced liver fibrosis relative to WT mice, as examined by ALT, hydroxyproline, histopathology, and profibrogenic gene. Absence of TSC1 in mesenchymal cells induced proliferation and prevented apoptosis in activated HSCs. However, there were no significant differences in oil-treated TSC1 CKO and WT mice. Rapamycin, restored these phenotypic changes by preventing myofibroblasts proliferation and enhancing their apoptosis. These findings revealed mTOR overactivation in mesenchymal cells aggravates CCl4- induced liver fibrosis and the rapamycin prevent its occurance.

Elevation of n-3/n-6 PUFAs ratio suppresses mTORC1 and prevents colorectal carcinogenesis associated with APC mutation.

Although epidemiological and preclinical studies have shown the preventative effect of n-3 polyunsaturated fatty acids (PUFAs) on colorectal cancer (CRC), the underlying molecular mechanisms are not clear. In this study, we revealed that elevation of n-3/n-6 PUFAs ratio suppress the mechanistic target of rapamycin complex 1 (mTORC1) and prevent colorectal tumorigenesis. The transgenic expression of fat-1, a desaturase that catalyzes the conversion of n-6 to n-3 PUFAs and produces n-3 PUFAs endogenously, repressed colorectal tumor cell growth and remarkably reduced tumor burden, and alleviated anemia as well as hyperlipidemia in APCMin/+ (adenomatous polyposis coli) mice, a classic CRC model that best simulates most clinical cases. In contrast to arachidonic acid (AA, C20:4 n-6), either Docosahexaenoic acid (DHA, C22:6 n-3), eicosapentaenoic acid (EPA, C20:5 n-3), or a combination of DHA and AA, efficiently inhibited the proliferation of CRC cell lines and promoted apoptosis in these cells. The ectopic expression of fat-1 had similar effects in colon epithelial cells with APC depletion. Mechanistically, elevation of n-3/n-6 ratio suppressed mTORC1 activity in tumors of APCMin/+ mice, CRC cell lines with APC mutation, and in normal colon epithelial cells with APC depletion. In addition, elevation of n-3/n-6 ratio repressed mTORC1 activity and inhibited adipogenic differentiation in preadipocytes with APC knockdown, as well as alleviated hyperlipidemia in APCMin/+ mice. Taken together, our findings have provided novel insights into the potential mechanism by which increase in n-3/n-6 PUFAs ratio represses CRC development, and also a new rationale for utilizing n-3 PUFAs in CRC prevention and treatment.

Solid-phase extraction combined with dispersive liquid-liquid microextraction for the determination of pyrethroid pesticides in wheat and maize samples.

A rapid, selective and sensitive sample preparation method based on solid-phase extraction combined with the dispersive liquid-liquid microextration was developed for the determination of pyrethroid pesticides in wheat and maize samples. Initially, the samples were extracted with acetonitrile and water solution followed phase separation with the salt addition. The following sample preparation involves a solid-phase extraction and dispersive liquid-liquid microextraction step, which effectively provide cleanup and enrichment effects. The main experimental factors affecting the performance both of solid-phase extraction and dispersive liquid-liquid microextration were investigated. The validation results indicated the suitability of the proposed method for routine analyze of pyrethroid pesticides in wheat and maize samples. The fortified recoveries at three levels ranged between 76.4 and 109.8% with relative standard deviations of less than 10.7%. The limit of quantification of the proposed method was below 0.0125 mg/kg for the pyrethoroid pesticides. The proposed method was successfully used for the rapid determination of pyrethroid residues in real wheat and maize samples from crop field in Beijing, China.

[Docosahexaenoic acid inhibits aflatoxin B1-induced migration and invasion in hepatocellular carcinoma cells in vitro].

OBJECTIVE: To investigate the effect of docosahexaenoic acid (DHA) on invasiveness of aflatoxin B1 (AFB1)-induced hepatocellular carcinoma cells in vitro. METHODS: HepG2.2.15 cells were exposed to different concentrations of AFB1 and DHA plus AFB1. The cell migration and invasion were assessed using wound-healing and Transwell assay, and flow cytometry was used to analyze the cell cycle changes. The ultrastructural changes of the cells were observed by transmission electron microscopy. RESULTS: Compared with the control group, the cells exposed to2 µmol/L AFB1 showed obviously enhanced migration and invasion with decreased cell ratio in G1/G1 phase and increased cell ratio in G2/M phase but no changes in S phase cells; transmission electron microscopy revealed the presence of multiple nucleoli and significantly increased mitochondria and Golgi apparatus in the exposed cells. Compared with AFB1-exposed cells, the cells treated with DHA and AFB1 showed decreased migration and invasion abilities, and the G1/G1 phase cells increased and G2/M phase cells decreased significantly; ultrastructurally, the cells contained single nucleoli with decreased mitochondria and vacuolization occurred in the cytoplasm. CONCLUSION: DHA can significantly inhibit AFB1-induced enhancement of cell migration and invasion in hepatocellular carcinoma cells in vitro.