Fertilization-independent seed development in Arabidopsis thaliana

We report mutants in Arabidopsis thaliana (fertilization-independent seed:fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers remain free of pollen. The three fis mutations map to loci on three different chromosomes. In fis1 and fis2 seeds, the autonomous endosperm nuclei are diploid and the endosperm develops to the point of cellularization; the partially developed seeds then atrophy. In these two mutants, proembryos are formed in a low proportion of seeds and do not develop beyond the globular stage. When FIS/fis plants are pollinated by pollen from FIS/FIS plants, approximately 50% of the resulting seeds contain fully developed embryos; these seeds germinate and form viable seedlings (FIS/FIS). The other 50% of seeds shrivel and do not germinate; they contain embryos arrested at the torpedo stage (FIS/fis). In normal sexual reproduction, the products of the FIS genes are likely to play important regulatory roles in the development of seed after fertilization.

Mutations in a newly identified GTPase gene cause autosomal dominant hereditary spastic paraplegia

The hereditary spastic paraplegias (HSPs; Strümpell-Lorrain syndrome, MIM number 18260) are a diverse class of disorders characterized by insidiously progressive lower-extremity spastic weakness (reviewed in refs. 1-3). Eight autosomal dominant HSP (ADHSP) loci have been identified, the most frequent of which is that linked to the SPG4 locus on chromosome 2p22 (found in approximately 42%), followed by that linked to the SPG3A locus on chromosome 14q11-q21 (in approximately 9%). Only SPG4 has been identified as a causative gene in ADHSP. Its protein (spastin) is predicted to participate in the assembly or function of nuclear protein complexes. Here we report the identification of mutations in a newly identified GTPase gene, SPG3A, in ADHSP affected individuals.

Increased risk of hepatocellular carcinoma in male hepatitis B surface antigen carriers with chronic hepatitis who have detectable urinary aflatoxin metabolite M1

We followed 145 men with chronic hepatitis B virus (HBV) hepatitis for 10 years to determine whether exposure to aflatoxin, or concomitant exposure to hepatitis C virus (HCV), or family history of hepatocellular carcinoma (HCC) increased the risk of developing HCC. We collected 8 monthly urine samples before beginning follow-up and pooled them to detect aflatoxin metabolite M1 (AFM1). AFM1 was detected in 78 (54%) of the subjects. The risk of HCC was increased 3.3-fold (with a 95% confidence interval of 1.2-8.7) in those with detectable AFM1 (above 3.6 ng/L). This relative risk was adjusted for age and for HCV status. The attributable risk from exposure to detectable AFM1 was 0.553 (0.087, 0.94). The relative risk of fatal cirrhosis for those with elevated AFM1 was 2.8 (0.6, 14.3), and the odds of having a persistently elevated alanine transaminase (ALT) were 2.5-fold greater in those with detectable AFM1 (P =.007). Concomitant infection with HCV increased the risk of HCC 5.8-fold (2. 0-17), adjusted for age and AFM1 status. A family history of HCC increased the risk of HCC 5.6-fold, adjusted for age and AFM1. Four men with detectable AFM1 and HCC all had missense mutation in codon 249 of the p53 gene in cancer tissues. This study shows that exposure to AFM1 can account for a substantial part of the risk of HCC in men with chronic HBV hepatitis and adds importantly to the evidence that HCV and family history of HCC increase the risk of HCC in men with chronic HBV hepatitis.

SMAC/Diablo mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events

p53-upregulated modulator of apoptosis (PUMA) is a BH3-only Bcl-2 family protein and an essential mediator of DNA damage-induced apoptosis. PUMA is localized in the mitochondria and induces apoptosis through the mitochondrial pathway. However, the mechanisms of PUMA-induced apoptosis remain unclear. In this study, we found that second mitochondria-derived activator of caspase (SMAC)/Diablo, a mitochondrial apoptogenic protein, mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events. SMAC is consistently released into the cytosol in colon cancer cells undergoing PUMA-induced apoptosis. In SMAC-deficient cells, execution of PUMA-induced apoptosis is abrogated, in company with decreases in caspase activation, cytosolic release of cytochrome c and collapse of mitochondrial membrane potential. Reconstituting SMAC expression restored these events in the SMAC-deficient cells. Furthermore, SMAC and agents that mimic the inhibitor of apoptosis proteins (IAPs) inhibition function of SMAC significantly sensitize cells to PUMA-induced apoptosis. These results demonstrate an important role of SMAC in executing DNA damage-induced and PUMA-mediated apoptosis and suggest that SMAC participates in a feedback amplification loop to promote cytochrome c release and other mitochondrial events in apoptosis.

Tumor necrosis factor-alpha-activated cell death pathways in NIT-1 insulinoma cells and primary pancreatic beta cells

Tumor necrosis factor-alpha (TNFalpha) is a potential mediator of beta cell destruction in insulin-dependent diabetes mellitus. We have studied TNF-responsive pathways leading to apoptosis in beta cells. Primary beta cells express low levels of the type I TNF receptor (TNFR1) but do not express the type 2 receptor (TNFR2). Evidence for TNFR1 expression on beta cells came from flow cytometry using monoclonal antibodies specific for TNFR1 and TNFR2 and from RT-PCR of beta cell RNA. NIT-1 insulinoma cells similarly expressed TNFR1 (at higher levels than primary beta cells) as detected by flow cytometry and radio-binding studies. TNF induced NF-kappaB activation in both primary islet cells and NIT-1 cells. Apoptosis in response to TNFalpha was observed in NIT-1 cells whereas apoptosis of primary beta cells required both TNFalpha and interferon-gamma (IFNgamma). Apoptosis could be prevented in NIT-1 cells by expression of dominant negative Fas-associating protein with death domain (dnFADD). Apoptosis in NIT-1 cells was increased by coincubation with IFNgamma, which also increased caspase 1 expression. These data show that TNF-activated pathways capable of inducing apoptotic cell death are present in beta cells. Caspase activation is the dominant pathway of TNF-induced cell death in NIT-1 cells and may be an important mechanism of beta cell damage in insulin-dependent diabetes mellitus.

Moldy sugarcane poisoning--a case report with a brief review

A five-year-old girl developed an acute encephalopathy after eating a piece of moldy sugarcane. Delayed symptomatic dystonia was the main effect; cranial CT scans revealed bilateral lenticular lucencies. This case is typical of moldy sugarcane poisoning cases previously reported only in China. 3-Nitropropionic acid produced by Arthrinium sp is the most likely etiologic agent.

PUMA mediates EGFR tyrosine kinase inhibitor-induced apoptosis in head and neck cancer cells

Overexpression of epidermal growth factor receptor (EGFR) is found in over 80% of head and neck squamous cell carcinomas (HNSCC) and associated with poor clinical outcomes. EFGR selective tyrosine kinase inhibitors (TKIs) or antibodies have recently emerged as promising treatments for solid tumors, including HNSCC, though the response rate to these agents is low. p53 upregulated modulator of apoptosis (PUMA), a BH3-only Bcl-2 family protein, is required for apoptosis induced by p53 and various chemotherapeutic agents. In this study, we show that PUMA induction is correlated with EGFR-TKI sensitivity, and is mediated through the p53 family protein p73beta and inhibition of the PI3K/AKT pathway. In some HNSCC cells, the gefitinib-induced degradation of oncogenic Delta Np63 seems to facilitate p73-mediated PUMA transcription. Inhibiting PUMA expression by small hairpin RNA (shRNA) impairs gefitinib-induced apoptosis. Furthermore, PUMA or BH3 mimetics sensitize HNSCC cells to gefitinib-induced apoptosis. Our results suggest that PUMA induction through p73 represents a new mechanism of EGFR inhibitor-induced apoptosis, and provide potential ways for enhancing and predicting the sensitivity to EGFR-targeted therapies in HNSCC.

Adrenocorticotrophin-induced hypertension in the rat: haemodynamic, metabolic and morphological characteristics

Adrenocorticotrophin (ACTH) administration has been systematically studied in man and sheep. It raises systolic blood pressure (SBP) in the rat, but this has been little studied. ACTH was injected once daily at 0.5 mg/kg for 12 days in male Sprague-Dawley rats (n = 19). Sham-injected animals were studied in parallel (n = 15). ACTH increased SBP from 94 +/- 4 to 121 +/- 4 mmHg (P less than 0.001), significantly greater (P less than 0.02) than sham injection. The SBP of ACTH-treated rats was significantly higher than that of sham-injected rats when the same animals were measured by both the tail-cuff method (ACTH, 126 +/- 3 mmHg; sham, 99 +/- 3 mmHg) and direct arterial cannulation (ACTH, 137 +/- 2 mmHg; sham, 123 +/- 3 mmHg): P less than 0.005 and P less than 0.001, respectively. There was a loss of body weight, and increased water intake and urine output in ACTH-treated animals compared with both control (P less than 0.001) and sham treatments (P less than 0.02). ACTH increased plasma [Na] (sham, 140 +/- 1 mmol/l; ACTH, 145 +/- 1 mmol/l; P less than 0.001) and urinary Na excretion compared with control (P less than 0.01) and sham injection (P less than 0.05), and also decreased plasma [K] (sham, 4.6 +/- 0.2 mmol/l; ACTH, 3.3 +/- 0.8 mmol/l; P less than 0.01) and increased urinary K excretion (P less than 0.01) compared with control. SBP in adrenalectomized animals (n = 10) was unchanged by ACTH. ACTH increased adrenal, renal, cardiac and brain weights compared with sham injection (P less than 0.05). There were no significant changes in vascular morphology, although ACTH treatment increased glomerular epithelial cell droplets and abolished the adrenal zona glomerulosa.

Androgen deprivation in LNCaP prostate tumour xenografts induces vascular changes and hypoxic stress, resulting in promotion of epithelial-to-mesenchymal transition

Background:

When single-agent androgen deprivation therapy (ADT) is administered for locally advanced prostate cancer, men usually relapse within 1–2 years with more malignant castrate-resistant disease. The reason for this is currently unknown. We now hypothesise that an initial treatment response that increases tumour hypoxia drives selection of more malignant tumours.

Methods:

The LNCaP prostate tumour xenografts were analysed for physiological (oxygen and vasculature) and genetic (PCR array) changes during longitudinal treatment with ADT (bicalutamide, 6 or 2 mg kg⁻¹ daily for 28 days).

Results:

Bicalutamide caused an immediate (within 24 h) dose-dependent fall in oxygenation in LNCaP-luc prostate tumours with a nadir of ≤0.1% oxygen within 3–7 days; this was attributed to a significant loss of tumour microvessels (window chamber study). The hypoxic nadir persisted for 10–14 days. During the next 7 days, tumours regrew, oxygenation improved and the vasculature recovered; this was inhibited by the VEGF inhibitor B20.4.1.1. Gene expression over 28 days showed marked fluctuations consistent with the physiological changes. Accompanying the angiogenic burst (day 21) was a particularly striking increase in expression of genes associated with epithelial-to-mesenchymal transition (EMT). In particular, insulin-like growth factor 1 (IGF-1) showed increases in mRNA and protein expression.

Conclusions:

Hypoxic stress caused by ADT promotes EMT, providing a mechanism for the cause of malignant progression in prostate cancer.

Synthesis and anticholinesterase activity of huperzine A analogues containing phenol and catechol replacements for the pyridone ring

Based upon modeling results obtained using the crystal structure of huperzine A in complex with acetylcholinesterase (AChE), two novel analogues of this potent AChE inhibitor were designed with phenol or catechol rings replacing the pyridone ring. From the modeling studies, the catechol analogue appeared capable of replacing one of the crystallographic waters bridging huperzine with Tyr 130 and Glu 199 of AChE. The synthesis of these materials by use of a palladium catalyzed bicycloannulation strategy is detailed together with the results of AChE inhibition assays.

The anticancer efficacy of paclitaxel liposomes modified with low-toxicity hydrophobic cell-penetrating peptides in breast cancer: an in vitro and in vivo evaluation

In our recent study, hydrophobic cell-penetrating peptides (CPPs) were demonstrated as an effective method of improving cancer treatment. To provide more evidence and broaden the application range for this promising strategy of improving cancer treatment, novel hydrophobic CPP-modified (PFV-modified) nanoliposomes loaded with paclitaxel, termed PFV-Lip-PTX, were developed as a treatment for breast cancer. Physicochemical evaluations of PFV-Lip-PTX revealed spheroid-like regular vesicles of about 120 nm in diameter with negative charge. An in vitro release study indicated that PTX was released from the liposomes in a controlled and sustained manner. A cellular uptake study indicated that PFV-Lip-PTX exhibited higher internalization efficiency in MCF-7 cells than non-modified liposomes. It was also demonstrated that PFV modification improved the cytotoxicity of PTX via a hydrophobic interaction between the PFV-Lip and cell lipid membranes compared with non-modified liposomes. Moreover, in vivo studies demonstrated that the PFV-modified liposomes led to highly efficient targeting and accumulation in an MCF-7 xenograft tumor and improved the antitumor efficacy of PTX. Finally, PFV-Lip-PTX showed low systemic toxicity evidenced by fewer changes in the body weights of mice and no visible histological changes in major healthy organs. Therefore, our results indicate that PFV-Lip-PTX has great potential in tumor-targeting and effective antitumor treatment.

Genetic diversity and phylogeographic structure of Bactrian camels shown by mitochondrial sequence variations

The Bactrian camel includes various domestic (Camelus bactrianus) and wild (Camelus ferus) breeds that are important for transportation and for their nutritional value. However, there is a lack of extensive information on their genetic diversity and phylogeographic structure. Here, we studied these parameters by examining an 809‐bp mtDNA fragment from 113 individuals, representing 11 domestic breeds, one wild breed and two hybrid individuals. We found 15 different haplotypes, and the phylogenetic analysis suggests that domestic and wild Bactrian camels have two distinct lineages. The analysis of molecular variance placed most of the genetic variance (90.14%, P < 0.01) between wild and domestic camel lineages, suggesting that domestic and wild Bactrian camel do not have the same maternal origin. The analysis of domestic Bactrian camels from different geographical locations found there was no significant genetic divergence in China, Russia and Mongolia. This suggests a strong gene flow due to wide movement of domestic Bactrian camels.

LncRNA SBF2-AS1 promotes hepatocellular carcinoma metastasis by regulating EMT and predicts unfavorable prognosis

OBJECTIVE

Recent studies have furthered our understanding of the function of long noncoding RNAs (lncRNAs) in numerous biological processes, including cancer. The present study aimed to investigate the expression of lncRNA SBF2-AS1 (SBF2-AS1) in patients with hepatocellular carcinoma (HCC) and to investigate its effect on HCC cells.

PATIENTS AND METHODS

Using quantitative reverse transcription-polymerase chain reaction, we detected SBF2-AS1 expression in HCC cell lines and primary tumor tissues. The associations between SBF2-AS1 expression and the clinicopathological factors and outcome of HCC patients were statistically analyzed. MTT assay and transwell assay were performed to determine the proliferation, migration and invasion, respectively. In addition, we evaluated the activation of Mesenchymal-epithelial transition (EMT) pathway by Western blot.

RESULTS

We found that SBF2-AS1 expression levels were significantly up-regulated in HCC tissues and cell lines compared with the corresponding noncancerous liver tissues and normal hepatic cell line. In addition, high SBF2-AS1 expression levels were correlated with vein invasion (p = 0.008) and TNM stage (p = 0.013). Furthermore, Kaplan-Meier survival analysis indicated that high expressions of SBF2-AS1 were correlated with shorter overall survival of HCC patients. Univariate and multivariate analysis identified high SBF2-AS1 expression as an unfavorable prognostic factor for overall survival. Further functional analysis demonstrated that knockdown of SBF2-AS1 significantly inhibited HCC cells proliferation, migration and invasion. Mechanistically, we found that SBF2-AS1 could promote the activation of EMT pathway, which was demonstrated by measuring the expression levels of EMT-related markers.

CONCLUSIONS

SBF2-AS1 might be considered as a novel molecule involved in HCC development, which provides a potential therapeutic target for HCC.

Infection with human immunodeficiency virus and hepatitis viruses in Chinese drug addicts

The prevalence of antibody against hepatitis C virus (anti-HCV) and five hepatitis B virus markers (HBVM) was measured in 176 Chinese drug addicts, of whom 23 were AIDS patients. Of 176 drug addicts, 147 were members of ethnic minorities while 29 were Han, the majority ethnic group. The total prevalence rates of anti-HCV and HBVM were 35.8% and 50.6% respectively, significantly different (P < 0.01). Anti-HCV and HBVM were together found in 22.7%. Similar prevalence rates were found among the different ethnic groups. Among the ethnic minorities, there was a significantly higher prevalence rate of anti-HCV in intravenous drug addicts (IVDA, 51.1%) than in oral drug addicts (20.3%). Furthermore, the prevalence of anti-HCV was significantly higher in needle-sharing abusers (60.4%) than in non-needle sharing ones (37.1%, P < 0.05). The prevalence of HBVM was also significantly higher in needle-sharing abusers (69.8%) than in non-needle sharing ones (34.3%). Prevalence of HBsAg was significantly higher in drug abusers with AIDS (47.8%) than in IVDA only (16.1%). The anti-HCV positive rates among ethnic minority people were: for the Yi people 69.2%, the Hui 55.6%, the Bai 53.9%, the Dai 26.8% and the Wa 23.1%. No obvious difference was identified for HBVM. The prevalence rates of HCV, HBV and HCV + HBV in IVDA showed no significant difference (P > 0.05) between the two regions. HIV, HCV and HBV infections may promote each other and be related to needle-sharing behaviour in drug abuse and to different subcultures and living habits.

Interleukin-18 and IL18 -607A/C and -137G/C gene polymorphisms in patients with penicillin allergy

This study investigated the association between polymorphisms (-607A/C and -137G/C) in the promoter region of the IL18 gene (which encodes interleukin [IL]-18) and serum levels of IL-18, using standard genotyping techniques (sequence specific primer-polymerase chain reaction) and an enzyme-linked immunosorbent assay, respectively, in patients allergic to penicillin. A higher frequency of A alleles and the AA genotype was found at position -607A/C in patients allergic to penicillin than in control subjects. For the -137G/C position, the C allele was more frequent in patients allergic to penicillin than in control subjects. Haplotype analysis showed that the -607A/-137C haplotype was more frequent in patients allergic to penicillin than in control subjects. The patients had a significantly higher serum IL-18 level than the control subjects. In conclusion, IL18 -607A/C and -137G/C promoter polymorphisms are associated with susceptibility to penicillin allergy. In particular, the -137G/C position appears to play an important role in IL18 expression.

Repairs of Partial Oblique Tendon Injuries: A Biomechanical Evaluation

This study evaluated the tensile properties of oblique partial tendon lacerations and the effects of peripheral sutures on their strength. Seventy-four fresh pig flexor digitorum profundus tendons were divided into eight groups and were transected across 90% of their diameter. The lacerations in the tendons of five of the groups were at 0°, 15°, 30°, 45°, and 60° to their transverse cross-section, respectively. In the other three groups the lacerations were 0°, 45°, and 60° to the cross-section and were repaired with running peripheral sutures. The tendons were subjected to load-to-failure tests in a tensile testing machine to determine the initial, 1 and 2 mm gap formation forces, and the ultimate strength. Obliquity of tendon lacerations affected the strength of partially lacerated tendons. The tendons with 45° and 60° oblique lacerations had a significantly lower ultimate strengths than those with transverse (0°), or 15° or 30° oblique lacerations. Running peripheral sutures significantly increased both the gap formation forces and the ultimate strength of the tendons with oblique partial lacerations.

Pulmonary function for pectus excavatum at long-term follow-up

PURPOSE

The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction.

METHODS

A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR).

RESULTS

TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases.

CONCLUSIONS

Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

An in vivo rat model for assessment of extrahepatic metabolism

INTRODUCTION

Xenobiotic metabolism in extrahepatic tissues has been extensively studied in vitro, but it is difficult to estimate in vivo the share of xenobiotic transformation in extrahepatic tissues for lack of a suitable approach. In this paper an in vivo rat model for assessment of extrahepatic metabolism is described, and the model was investigated using the conversion of lidocaine to monoethylglycinexylidide (MEGX).

METHODS

The rats were anesthetized with ethyl ether inhalation. The liver was exposed, the liver artery ligated, and the portal vein was clamped at its distal end. The left hepatic lobe was partly excised along its inferior margin, and a heparinized silicone catheter, diameter 0.2 cm, was inserted into the portal and left hepatic veins to allow the recirculation of portal vein blood. A sham operation was performed in the control group.

RESULTS

Phenol red test showed that hepatic blood supply was absolutely blocked in model rats. At 30 min after establishing the portal-cavum bypass, the renal function and electrolytes did not change, but serum glucose decreased by 64.4 +/- 30.4%; 30 min after intravenous administration of 1.0% lidocaine 2 mg x kg(-1), serum MEGX in model rats was 32.0 +/- 7.14% of that in the control group, which mostly existed in a free form and was not induced by phenobarbital pretreatment.

DISCUSSION

The model is easy to establish and provides an in vivo method to study the extrahepatic metabolism of xenobiotics.

Molecular phylogeny of the Bactrian camel based on mitochondrial Cytochrome b gene sequences

The Bactrian camel is an important domesticated animal providing milk, meat, and other products in desert countries. In this study, 111 individuals representing 11 domestic Bactrian camel breeds from China, Mongolia, Russia, and one wild Bactrian camel group from Mongolia were selected for the preparation of mitochondrial DNA. The 1140-bp fragments of the cytochrome b gene (Cytb) were amplified by polymerase chain reaction and sequenced directly. Sequences of the 92 domestic and 19 wild Bactrian camel samples were analyzed with DNASTAR, and a phylogenic tree was constructed using MEGA. The analysis revealed sixteen haplotypes among the samples that were divided into two haplogroups: a domestic haplogroup (H1-H13, H15, and H16) and a wild haplogroup (H14). Haplotype diversity values were from 0.356 in the HosZogdort, to 0.889 in the Sunit Bactrian camel breed. The Sunit breed displayed the highest nucleotide diversity value (0.00115), and the HosZogdort breed had the lowest value (0.00031). All domestic Bactrian camels formed a single monophyletic lineage that is the sister group to wild Bactrian camels, a finding consistent with a single domestication event and independent maternal inheritance since domestication. In addition, the most common mitochondrial haplotypes (H1, H3, and H4) were shared between Chinese, Mongolian, and Russian domestic Bactrian camels, which indicated that there was no distinguishing geographic structure among the domestic breeds from these three regions. These findings provide important insights into patterns of relatedness among Bactrian camels from the Chinese, Mongolian, and Russian regions.

Primary cultures of mouse small intestinal epithelial cells using the dissociating enzyme type I collagenase and hyaluronidase

The epithelium is a highly dynamic system, which plays a crucial role in the homeostasis of the intestinal tract. However, studies on the physiological and pathophysiological functions of intestinal epithelial cells (IECs) have been hampered due to lack of normal epithelial cell models. In the present study, we established a reproducible method for primary culture of mouse IECs, which were isolated from the viable small intestinal crypts of murine fetuses (on embryonic day 19), using type I collagenase and hyaluronidase in a short span of time (≤20 min). With this method, continuously growing mouse IECs, which can be subcultured over a number of passages, were obtained. The obtained cell lines formed a tight cobblestone-like arrangement, displayed long and slender microvilli, expressed characteristic markers (cytokeratin 18 and Notch-1), and generated increasing transepithelial electrical resistance and low paracellular permeability during in vitro culture. The cells also had enzymatic activities of alkaline phosphatase and sucrase-isomaltase, and secreted various cytokines (IL-1β, IL-6, IL-8, and monocyte chemoattractant protein-1), responding to the stimulation of Escherichia coli. These results show that the primary-cultured mouse IECs obtained by the method established here had the morphological and immunological characteristics of IECs. This culture system can be a beneficial in vitro model for studies on mucosal immunology and toxicology.