The LIM-only factor LMO4 regulates expression of the BMP7 gene through an HDAC2-dependent mechanism, and controls cell proliferation and apoptosis of mammary epithelial cells

The nuclear LIM-only protein 4 (LMO4) is upregulated in breast cancer, especially estrogen receptor-negative tumors, and its overexpression in mice leads to hyperplasia and tumor formation. Here, we show that deletion of LMO4 in the mammary glands of mice leads to impaired lobuloalveolar development due to decreased epithelial cell proliferation. With the goal of discovering potential LMO4-target genes, we also developed a conditional expression system in MCF-7 cells for both LMO4 and a dominant negative (DN) form of its co-regulator, cofactor of LIM domains (Clim/Ldb/Nli). We then used DNA microarrays to identify genes responsive to LMO4 and DN-Clim upregulation. One of the genes common to both data sets was bone morphogenic protein 7 (BMP7), whose expression is also significantly correlated with LMO4 transcript levels in a large dataset of human breast cancers, suggesting that BMP7 is a bona fide target gene of LMO4 in breast cancer. Inhibition of BMP7 partially blocks the effects of LMO4 on apoptosis, indicating that BMP7 mediates at least some functions of LMO4. Gene transfer studies show that LMO4 regulates the BMP7 promoter, and chromatin immunoprecipitation studies show that LMO4 and its cofactor Clim2 are recruited to the BMP7 promoter. Furthermore, we demonstrate that HDAC2 recruitment to the BMP7 promoter is inhibited by upregulation of LMO4 and that HDAC2 knockdown upregulates the promoter. These studies suggest a novel mechanism of action for LMO4: LMO4, Clim2 and HDAC2 are part of a transcriptional complex, and increased LMO4 levels can disrupt the complex, leading to decreased HDAC2 recruitment and increased promoter activity.

Influences of buffer systems on chondrocyte growth during long-term culture in alginate

OBJECTIVE

Chondrocyte behavior is very sensitive to culture environment such as physical and biochemical conditions. As extracellular pH (pHo) and the existence of bicarbonate could affect the chondrocyte fate, hence, the purpose of this study is to investigate the buffer system effect on chondrocyte fate during relatively long-term culture.

METHODS

In order to examine whether effects seen were due to bicarbonate or to pHo, we had to devise a system which could differentiate between the two effects. Culture media buffered by N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid (HEPES) only and the combination of HEPES and bicarbonate were used. Bovine articular chondrocytes were cultured in alginate beads for up to 12 days. pHo was kept constant by culture of 3 beads in 2 ml culture medium. Cell density, intracellular pH (pHi) and glycosaminoglycan (GAG) were measured at day 5 and day 12. Cell morphology, distribution and viability in alginate beads were monitored over 12 days of culture.

RESULTS

Compared to culture in the absence of bicarbonate, a higher proliferation rate of chondrocytes was observed in the presence of bicarbonate. pHi was more alkaline, about 0.2 pH unit, in the presence of bicarbonate than that in the absence of bicarbonate. About 50% more GAG was deposited in alginate beads when chondrocytes were cultured in the combination of HEPES and bicarbonate, compared to chondrocytes cultured in the absence of NaHCO3 at the end of 12 days of culture.

CONCLUSION

The presence of bicarbonate results in more alkaline in the pHi of bovine chondrocytes after long-term culture. The combination of bicarbonate and HEPES in culture medium improves cell growth, matrix production in three-dimensional alginate beads.

Synergistic effects of ethosomes and chemical enhancers on enhancement of naloxone permeation through human skin

The purpose of this study was to investigate the effects of ethosomes, chemical enhancers and their binary combination on the in vitro permeability enhancement of naloxone through human skin. Franz diffusion cells were used for the percutaneous absorption studies. Propylene glycol (PG), N,N-dimethyl formamide (N,N-DMF), N,N-dimethyl acetamide (N,N-DMA), dimethyl sulfoxide (DMSO), Azone and polyethylene glycol 400 (PEG400), were chosen as the chemical enhancers. Naloxone ethosomes showed 11.68 times increase in steady-state flux compared to phosphate buffered solution (PBS). Ethosomes in combination with chemical enhancers synergistically increased (p < 0.05) in vitro flux of naloxone. Azone 3% + PG7% pretreated in ethosomal form dramatically enhanced the skin permeation of naloxone in vitro compared with ethosomes (steady-state flux: 96.75 +/- 5.70 microg x cm(-2) x h(-1) vs 20.56 +/- 1.67 microg x cm(-2) x h(-1)). Ethosomal carrier and enhancers accumulated in the skin after 24 h were greater than that of PBS.

Inhibitory effects of sildenafil on gastric motility and gastric slow waves in dogs

The aim of this study was to investigate the effects of sildenafil on gastric motility and gastric slow waves in dogs. The study was performed in healthy dogs and composed of three experiments. The first experiment was designed to study the effects of sildenafil on gastric emptying and gastric slow waves. The second experiment was used to investigate the effects of sildenafil on gastric tone. The third experiment was used to study the effects of sildenafil on postprandial antral contractions. (i) Sildenafil did not alter gastric emptying of liquid. (ii) Sildenafil had no effects on dominant frequency and percentage of normal gastric slow waves. The dominant power of gastric slow waves was, however, significantly reduced with sildenafil (P < 0.02). (iii) Fasting gastric volume with sildenafil was significantly higher than that at baseline (P < 0.0005) or in the control session (P < 0.002). However, the postprandial gastric volume was not altered with sildenafil. (iv) Sildenafil inhibited gastric antral motility. The contraction index was 338.5 +/- 39.99 at baseline and 122.5 +/- 20.3 after the injection of sildenafil (P = 0.003). Sildenafil inhibits fundic tone and antral motility but does not seem to delay gastric emptying of liquid in dogs. The amplitude but not the frequency or regularity of the gastric slow wave is inhibited by sildenafil.

Menstrual cycle lengths and bone mineral density: a cross-sectional, population-based study in rural Chinese women ages 30-49 years

INTRODUCTION

The menstrual cycle involves periodic fluctuations in estrogen and progesterone levels. Longer cycles have been associated with longer follicular phase, delayed estrogen peak and a lower mean oestradiol level of the entire cycle.

METHODS

We hypothesized that prolonged menstrual cycle length is associated with decreased bone mineral density (BMD) in a population of pre- and perimenopausal women. This population-based cross-sectional study was conducted in rural Anhui province, China. It includes 4,771 women, aged 30 to 49 years, who did not smoke or drink alcohol, and did not use oral contraceptives or breastfeed during the previous year. Dual-energy X-ray absorptionometry (DEXA) BMD measurements were taken at four skeletal sites: whole body, total hip, femoral neck and lumbar spine. Menstrual cycle characteristics (polymenorrhea, short normal, long normal, oligomenorrhea, 90-day amenorrhea, irregular cycle) in the prior year were assessed by questionnaire.

RESULTS

Prolonged menstrual cycle was consistently associated with decreased BMD at whole body, total hip, and femoral neck in both age 30-39, and age 40-49 stratum (p(trend)<0.05). Prolonged menstrual cycle was also associated with decreased lumbar spine BMD for women aged 40-49 (p(trend)<0.05). Among women with normal cycles aged 30-39, menstrual cycle length in the previous year was inversely associated with whole-body BMD (p<0.05). Women with 90-day amenorrhea had significantly lower mean total hip and femoral neck BMD relative to women with short normal cycles in the 30-39 age group; and had significantly lower whole body and total hip BMD relative to short normal cycles in the 40-49 age group. BMD in polymenorrheic women did not differ from BMD in women with short normal cycles at any of the skeletal sites.

CONCLUSIONS

We conclude that prolonged menstrual cycle length is associated with decreased BMD in pre- and perimenopausal women in this population.

Influence of acute normovolaemic haemodilution on the dose-response relationship and time course of action of cisatracurium besylate

BACKGROUND

Acute normovolaemic haemodilution (ANH) is an efficacious blood conservation strategy aiming at avoiding allogeneic blood transfusion. ANH was shown to increase the potency of vecuronium, atracurium, and rocuronium. The aim of our study was to investigate whether cisatracurium potency is altered with ANH.

METHODS

Using the Relaxometer mechanomyograph, we compared cisatracurium dose-response relationship and time course of action in 60 patients randomly allocated to the ANH or control groups. Patients in each group were randomly allocated to receive one of three cisatracurium doses (30, 40, 50 microg kg(-1)) followed by a second supplemental dose to reach a total of 100 microg kg(-1).

RESULTS

ANH did not result in a significant shift in cisatracurium log dose-probit dose-response curve. There was no significant difference in mean (95% confidence intervals) ED(50), ED(90), and ED(95) (effective doses required for 50, 90, and 95% first twitch depression) between the ANH group [29.5 (27-32), 50.4 (47.4-53.4), 58.7 (55.3-62) microg kg(-1)] and the control group [28.2 (25.3-31), 47.6 (44.9-50.3), 55.3 (52.5-58.1) microg kg(-1)], whereas there was no difference in mean (SD) Dur(25) and Dur(0.8) (time until 25% first twitch and 0.8 train-of-four ratio recoveries) between the ANH group [40.8 (5.9), 64.7 (8.4) min] and the control group [42.2 (7.6), 66.5 (10.7) min].

CONCLUSIONS

Our results demonstrated that unlike other previously reported neuromuscular blocking drugs, ANH did not alter cisatracurium potency. Thus, cisatracurium would be the neuromuscular blocking drug of choice in patients who undergo surgery with ANH, as no dose adjustments are required.

Designing and transgenic expression of melanin gene in tobacco trichome and cotton fiber

In Streptomyces antibioticus, there are two genes TYRA and ORF438 required for the melanin biogenesis. To investigate whether expression of these two genes in cotton can change cotton fiber colour, we modified the TYRA and ORF438 genes to make their codon usage closer to the codon preference of cotton fiber genes. The resulting versions of these two genes were referred to as DTYRA and DORF438, respectively. Vacuolar targeting signals were also added to their ends. Under the cotton fiber specific LTP3 promoter, DORF438 and DTYRA were first transformed into model plant tobacco (Nicotiana tabacum). Molecular analyses showed that both the DORF438 and DTYRA genes were successfully expressed in transgenic plants, and the melanin deposition was observed in the trichomes of transgenic tobacco. Excitedly, when the same DORF438 and DTYRA expression cassettes were transformed into cotton (Gossypium hirsutum L.) by pollen tube pathway, the colour of cotton fiber changed from white to brown. Molecular analyses confirmed that both genes were transformed into cotton and expressed successfully. All these results indicate that the synthesized DOFR438 and DTYRA genes can work well in tobacco and cotton. Our study may provide a potential method for modifying the colour of cotton fiber.

Preptin, another peptide product of the pancreatic beta-cell, is osteogenic in vitro and in vivo

Several hormones that regulate nutritional status also impact on bone metabolism. Preptin is a recently isolated 34-amino acid peptide hormone that is cosecreted with insulin and amylin from the pancreatic beta-cells. Preptin corresponds to Asp(69)-Leu(102) of pro-IGF-II. Increased circulating levels of a pro-IGF-II peptide complexed with IGF-binding protein-2 have been implicated in the high bone mass phenotype observed in patients with chronic hepatitis C infection. We have assessed preptin's activities on bone. Preptin dose-dependently stimulated the proliferation (cell number and DNA synthesis) of primary fetal rat osteoblasts and osteoblast-like cell lines at periphysiological concentrations (>10(-11) M). In addition, thymidine incorporation was stimulated in murine neonatal calvarial organ culture, likely reflecting the proliferation of cells from the osteoblast lineage. Preptin did not affect bone resorption in this model. Preptin induced phosphorylation of p42/p44 MAP kinases in osteoblastic cells in a dose-dependent manner (10(-8)-10(-10) M), and its proliferative effects on primary osteoblasts were blocked by MAP kinase kinase inhibitors. Preptin also reduced osteoblast apoptosis induced by serum deprivation, reducing the number of apoptotic cells by >20%. In vivo administration of preptin increased bone area and mineralizing surface in adult mice. These data demonstrate that preptin, which is cosecreted from the pancreatic beta-cell with amylin and insulin, is anabolic to bone and may contribute to the preservation of bone mass observed in hyperinsulinemic states such as obesity.

Genetic polymorphisms of the urea transporter gene are associated with antihypertensive response to nifedipine GITS

Nifedipine GITS has diuretic and natriuretic properties, which may enhance its antihypertensive efficacy. We assessed contributions of polymorphisms in the urea transporter-A gene (SLC14A2) to interindividual variations in blood pressure (BP) response to nifedipine treatment. 405 subjects from a single Chinese county received a single oral dose of 30 mg nifedipine GITS (gastrointestinal therapeutic system) daily for 16 days. We genotyped two SNPs in SLC14A2 and found significant associations for the Val227Ile (rs1123617) and Ala357Thr (rs3745009) polymorphisms with BP response to nifedipine treatment. After treatment, subjects with either Ala357/Thr357 or Thr357/Thr357 genotypes had significantly smaller mean changes in systolic BP (SBP) (beta +/- SE = -2.87 +/- 1.24 mmHg, p = 0.020) and diastolic BP (DBP) (beta +/- SE = -1.69 +/- 0.62 mmHg, p = 0.006) compared to those with the Ala357/Ala357 genotype. Subjects with either Val227/Ile227 or Ile227/Ile227 genotypes had significantly larger mean changes in SBP (beta +/- SE = 3.13 +/- 1.19, p = 0.009) and DBP (beta +/- SE = 1.50 +/- 0.60 mmHg, p = 0.013) compared with those with the Val227/Val227 genotype after treatment. Subjects carrying both the Ala357/Ala357 genotype in the Ala357Thr polymorphism and either Val227/Ile227 or Ile227/Ile227 genotypes in the Val227Ile polymorphism had the highest mean change in SBP and DBP. Our study supports the conclusion that polymorphisms in the SLC14A2 gene can predict the antihypertensive efficacy of nifedipine GITS.

Expression of elevated levels of pro-inflammatory cytokines in SARS-CoV-infected ACE2+ cells in SARS patients: relation to the acute lung injury and pathogenesis of SARS

The authors have previously shown that acute lung injury (ALI) produces a wide spectrum of pathological processes in patients who die of severe acute respiratory syndrome (SARS) and that the SARS coronavirus (SARS‐CoV) nucleoprotein is detectable in the lungs, and other organs and tissues, in these patients. In the present study, immunohistochemistry (IHC) and in situ hybridization (ISH) assays were used to analyse the expression of angiotensin‐converting enzyme 2 (ACE2), SARS‐CoV spike (S) protein, and some pro‐inflammatory cytokines (PICs) including MCP‐1, TGF‐β1, TNF‐α, IL‐1β, and IL‐6 in autopsy tissues from four patients who died of SARS. SARS‐CoV S protein and its RNA were only detected in ACE2⁺ cells in the lungs and other organs, indicating that ACE2‐expressing cells are the primary targets for SARS‐CoV infection in vivo in humans. High levels of PICs were expressed in the SARS‐CoV‐infected ACE2⁺ cells, but not in the uninfected cells. These results suggest that cells infected by SARS‐CoV produce elevated levels of PICs which may cause immuno‐mediated damage to the lungs and other organs, resulting in ALI and, subsequently, multi‐organ dysfunction. Therefore application of PIC antagonists may reduce the severity and mortality of SARS. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The contribution of GJB2 mutations to slight or mild hearing loss in Australian elementary school children

BACKGROUND

There is a lack of information on prevalence, cause and consequences of slight/mild bilateral sensorineural hearing loss (SNHL) in children. We report the first systematic genetic analysis of the GJB2 gene in a population-derived sample of children with slight/mild bilateral SNHL.

METHODS

Hearing tests were conducted in 6240 Australian elementary school children in Grades 1 and 5. 55 children (0.88%) were found to have a slight/mild sensorineural hearing loss. 48 children with slight/mild sensorineural hearing loss and a matched group of 90 children with normal hearing participated in a genetic study investigating mutations in the GJB2 gene, coding for connexin 26, and the presence of the del(GJB6-D13S1830) and del(GJB6-D13S1854) deletions in the GJB6 gene, coding for connexin 30.

RESULTS

Four of 48 children with slight/mild sensorineural hearing loss were homozygous for the GJB2 V37I change. The four children with homozygous V37I mutations were all of Asian background and analysis of SNPs in or near the GJB2 gene suggests that the V37I mutation arose from a single mutational event in the Asian population.

DISCUSSION

Based on the prevalence of carriers of this change we conclude that V37I can be a causative mutation that is often associated with slight/mild sensorineural hearing loss. No other children in the slight/mild hearing loss group had a hearing loss related to a GJB2 mutation. One child with normal hearing was homozygous for the R127H change and we conclude that this change does not cause hearing loss. Two children of Asian background were carriers of the V37I mutation. Our data indicate that slight/mild sensorineural hearing loss due to the GJB2 V37I mutation is common in people of Asian background.

Effects of Ischemia-Reperfusion Injury on Apolipoprotein M Expression in the Liver

The present study investigated the expression pattern of apolipoprotein M (apoM) mRNA in a rat model of hepatic ischemia-reperfusion injury (IRI). Animals were ischemic for 1 hour followed by various reperfusion times. As expected, serum alanine aminotransferase levels were significantly increased under IRI, which indicated the severity of liver injury. Hepatic mRNA levels of HSP70, which is the most common characterized protein within the family of heat-shock proteins (HSP), were significantly increased after 0.5 to 3 hours of IRI. Plasma C-reactive protein, high-density lipoprotein-cholesterol, and lipoprotein (a) levels were significantly increased after 1-hour ischemia followed by 0.5 to 3 hours of reperfusion. Interestingly, similar to HSP70, apoM mRNA levels in the liver were gradually increased after 0.5 to 3 hours of IRI, whereas it returned to a lower level after 6 or 24 hours of IRI, which indicated that hepatic apoM expression was significantly influenced by the acute phase of IRI. However, plasma apoM levels were not increased in parallel, even slightly decreasing after 0.5 or 1 hour of IRI. We concluded that apoM mRNA expression pattern, like HSP70, in the liver showed rapid, significant changes during hepatic local IRI.

The analysis of 51 genes in DSM-IV combined type attention deficit hyperactivity disorder: association signals in DRD4, DAT1 and 16 other genes

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, starting in early childhood and persisting into adulthood in the majority of cases. Family and twin studies have demonstrated the importance of genetic factors and candidate gene association studies have identified several loci that exert small but significant effects on ADHD. To provide further clarification of reported associations and identify novel associated genes, we examined 1,038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes. Analysis used within family tests of association in a sample of 776 DSM-IV ADHD combined type cases ascertained for the International Multi-centre ADHD Gene project. We found nominal significance with one or more SNPs in 18 genes, including the two most replicated findings in the literature: DRD4 and DAT1. Gene-wide tests, adjusted for the number of SNPs analysed in each gene, identified associations with TPH2, ARRB2, SYP, DAT1, ADRB2, HES1, MAOA and PNMT. Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples.

CYP2C9 Ile359Leu polymorphism, plasma irbesartan concentration and acute blood pressure reductions in response to irbesartan treatment in Chinese hypertensive patients

Our previous study demonstrated that the CYP2C9*3 gene variant was significantly associated with elevated plasma irbesartan concentration and blood pressure decline, assessed by a 4-week follow-up and revisit following daily administration of irbesartan. We conducted a further analysis to examine the acute effects of the CYP2C9 polymorphism on plasma concentration and blood pressure through remeasurement 6 h after administration of irbesartan. We used an extreme-sampling approach by selecting individuals from the top and bottom deciles of blood pressure response residuals to irbesartan from the previous study population in Anhui, Taihu, and Dongzhi Counties, in China. A total of 196 subjects were available for the analysis. Pre- and posttreatment systolic and diastolic blood pressures (SBP and DBP), and venous blood samples (0.5, 2, and 6 h following the first treatment) were collected from each individual. Plasma irbesartan concentrations were determined by a standard HPLC/fluorescence method. The observed frequencies were 97.7% for CYP2C9*1 (Ile359) and 2.3% for CYP2C9*3 (Leu359). Subjects with the CYP2C9*1/CYP2C9*3 genotype had significantly higher plasma irbesartan concentrations when compared with those with the CYP2C9*1/CYP2C9*1 genotype (beta +/- SE = 81 +/- 36) and greater DBP response (beta +/- SE = 5.6 +/- 2.5 mmHg) at the 6-h time point after adjusting for important confounders. Our finding suggests that the CYP2C9*3 gene variant significantly alters the plasma concentration and acute DBP response at the 6-h point following irbesartan treatment in Chinese hypertensive patients.

Polymorphisms in the HBB gene relate to individual cardiorespiratory adaptation in response to endurance training

OBJECTIVE

The crucial role of haemoglobin in endurance performance has been well documented. We examined whether polymorphisms in the HBB gene modified aerobic capacity.

METHODS

102 recruits were trained by running 5000 m three times per week for 18 weeks. Exercise intensity progressively increased from an initial heart rate corresponding to 95% of the individual baseline ventilatory threshold during the first 10 weeks to 105% during the last 8 weeks. The phenotypes measured were running economy and VO(2)max. Running economy was determined by measuring submaximal VO(2) for 5 min at a constant running speed of 12 km.h(-1) and VO(2)max was obtained during an incremental test to exhaustion. Genomic DNA was extracted from white cells of peripheral blood and the -551C/T, intron2,+16C/G and +340 A/T genotypes were examined relative to the TAA site variants by PCR-RFLP.

RESULTS

Genotype distributions were in Hardy-Weinberg equilibrium at three loci. None of the running economy and VO(2)max-related traits were associated with the three polymorphisms or haplotypes at baseline, while the training response of running economy was associated with -551C/T and intron2,+16C/G polymorphisms. Subjects homozygous for intron2,+16C/C or -551C/C had decreased oxygen cost of running compared to the other individuals.

DISCUSSION

It was concluded that the -551C/C or intron2,+16C/C genotype might explain part of the individual variation in the cardiorespiratory adaptation to endurance training.

Expression of PPARdelta in multistage carcinogenesis of the colorectum: implications of malignant cancer morphology

Whether peroxisome proliferator-activated receptor (PPAR) delta is a good target for the chemoprevention and/or treatment of colorectal cancer (CRC) remains controversial. Our goal was to examine PPARdelta expression in multistage carcinogenesis of the colorectum and to assess the relevance of PPARdelta in CRC. Immunohistochemical analysis indicated that PPARdelta expression increased from normal mucosa to adenomatous polyps to CRC. In cancer tissues, the PPARdelta protein was accumulated only in those cancer cells with highly malignant morphology, as represented by a large-sized nucleus, round-shaped nucleus, and presence of clear nucleoli. Interestingly, the cancer tissue often contained both PPARdelta-positive and -negative areas, each retaining their respective specific morphological features. Moreover, this pattern persisted even when PPARdelta-positive and -negative cells were aligned next to each other within a single cancer nest or gland and was present in the majority of CRC cases. Immunohistochemistry for Ki-67 proliferation marker showed no significant correlation between Ki-67 and PPARdelta in CRC samples. Based on Western blot analysis and quantitative RT-PCR, high PPARdelta protein expression correlated with high PPARdelta mRNA levels. Peroxisome proliferator-activated receptor delta may have a supporting role in tumorigenesis, and the close association between PPARdelta expression and malignant morphology of CRC cells suggests a pivotal role in cancer tissue.