Effect of gut microbiota-derived metabolites and extracellular vesicles on neurodegenerative disease in a gut-brain axis chip

A new perspective suggests that a dynamic bidirectional communication system, often referred to as the microbiome-gut-brain axis, exists among the gut, its microbiome, and the central nervous system (CNS). This system may influence brain health and various brain-related diseases, especially in the realms of neurodevelopmental and neurodegenerative conditions. However, the exact mechanism is not yet understood. Metabolites or extracellular vesicles derived from microbes in the gut have the capacity to traverse the intestinal epithelial barrier or blood-brain barrier, gaining access to the systemic circulation. This phenomenon can initiate the physiological responses that directly or indirectly impact the CNS and its function. However, reliable and controllable tools are required to demonstrate the causal effects of gut microbial-derived substances on neurogenesis and neurodegenerative diseases. The integration of microfluidics enhances scientific research by providing advanced in vitro engineering models. In this study, we investigated the impact of microbe-derived metabolites and exosomes on neurodevelopment and neurodegenerative disorders using human induced pluripotent stem cells (iPSCs)-derived neurons in a gut-brain axis chip. While strain-specific, our findings indicate that both microbial-derived metabolites and exosomes exert the significant effects on neural growth, maturation, and synaptic plasticity. Therefore, our results suggest that metabolites and exosomes derived from microbes hold promise as potential candidates and strategies for addressing neurodevelopmental and neurodegenerative disorders.

Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Effect of gut microbiome-derived metabolites and extracellular vesicles on hepatocyte functions in a gut-liver axis chip

Metabolism, is a complex process involving the gut and the liver tissue, is difficult to be reproduced in vitro with conventional single cell culture systems. To tackle this challenge, we developed a gut-liver-axis chip consisting of the gut epithelial cell chamber and three-dimensional (3D) uniform-sized liver spheroid chamber. Two cell culture chamber compartments were separated with a porous membrane to prevent microorganisms from passing through the chamber. When the hepG2 spheroids cultured with microbiota-derived metabolites, we observed the changes in the physiological function of hepG2 spheroids, showing that the albumin and urea secretion activity of liver spheroids was significantly enhanced. Additionally, the functional validation of hepG2 spheroids treated with microbiota-derived exosome was evaluated that the treatment of the microbiota-derived exosome significantly enhanced albumin and urea in hepG2 spheroids in a gut-liver axis chip. Therefore, this gut-liver axis chip could be a potentially powerful co-culture platform to study the interaction of microbiota and host cells.

Comparison of trans-radial access and femoral access in cardiogenic shock patient who had undergone primary percutaneous coronary intervention from SMART RESCUE trial

Introduction

Throughout the years of percutaneous coronary intervention (PCI), the debate regarding access route, whether it being trasns-radial or femoral, is an ongoing agenda yet to be solved. Recent guidelines suggest trans-radial approach as an option to be considered in acute coronary syndrome (ACS). However, data on cardiogenic shock patients undergoing PCI is relatively sparse.

Purpose

Compare the clinical implication of trans-radial and femoral approach in cardiogenic shock patients who had undergone PCI.

Method

Cardiogenic shock patients who had undergone PCI from January 2014 to December of 2018 were enrolled. Patients were divided according to their access route respectfully. Primary outcome was composite endpoints including all-cause death, re-admission due to heart failure, myocardial infarction (MI) and cerebrovascular accident.

Result

A total of 694 (572 via femoral approach, 122 via radial approach) cardiogenic shock patients who received PCI were enrolled. Mean age femoral and radial groups was 66.59±12.51 and 66.66±12.8 respectfully. Disease severity was higher for femoral patients compared to radial patients as represented by their LM involvement, mechanical organ support (extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation), left ventricular ejection fraction (LVEF) and vasoactive inotropic score. Cox regression analysis after adjusting for conventional risk factors showed that femoral route was a poor prognosticator with respect to composite endpoints (HR=2.059, 95% CI 1.249–3.397, p value = 0.005). Radial approach patients had higher survival probability compared to femoral approach patients (Figure 1).

Conclusion

Radial approach in cardiogenic shock patients who are in need for PCI with relatively less severe clinical condition could be a reasonable option for access route.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Inha University Hospital

Prognostic impact of plasma glucose on cardiogenic shock patients with or without diabetes ellitus: smart rescue trial

Background

Even though the presence of hyperglycemia has shown to affect the clinical outcome of cardiogenic shock patients, the extent of hyperglycemia and its association with prognosis have not been fully addressed in large population

Purpose

Investigate the clinical relationship between hyperglycemic status and in-hospital mortality in cardiogenic shock patients

Method

A total of 1,177 consecutive cardiogenic shock patients were enrolled from January 2014 to December of 2018 at 12 hospitals in South Korea. The primary outcome was in-hospital mortality. Patients were divided into four groups according to their initial plasma glucose level in each of diabetes patients (n=752) and non-diabetes patients (n=425); group 1 (≤8 mmol/L), group 2 (8–12 mmol/L), group 3 (12–16 mmol/L) and group 4 (≥16 mmol/L).

Results

The groups with higher admission plasma glucose were associated with lower systolic blood pressure and higher lactic acid level in both diabetic and non-diabetic patients. In-hospital mortality increased in groups with higher admission plasma glucose level in non-diabetic patients (group-1:24.2%, group-2: 28.6%, group-3: 38.1%, group-4: 49.0%, p<0.01) whereas in diabetic patients, mortality and admission plasma glucose level showed no significant association (group-1: 45%, group-2: 35.4%, group-3: 33.3%, group-4: 43.1%, p=0.26). Even after Multivariate analysis, high plasma glucose was an independent predictor of in-hospital mortality in non-diabetic patients

Conclusion

In cardiogenic shock patients, plasma glucose obtained at admission was associated with in-hospital mortality in non-diabetic patients

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Inha University hospital

Contributions of the microbiome to intestinal inflammation in a gut-on-a-chip

The intestinal microbiome affects a number of biological functions of the organism. Although the animal model is a powerful tool to study the relationship between the host and microbe, a physiologically relevant in vitro human intestinal system has still unmet needs. Thus, the establishment of an in vitro living cell-based system of the intestine that can mimic the mechanical, structural, absorptive, transport and pathophysiological properties of the human intestinal environment along with its commensal bacterial strains can promote pharmaceutical development and potentially replace animal testing. In this paper, we present a microfluidic-based gut model which allows co-culture of human and microbial cells to mimic the gastrointestinal structure. The gut microenvironment is recreated by flowing fluid at a low rate (21 μL/h) over the microchannels. Under these conditions, we demonstrated the capability of gut-on-a-chip to recapitulate in vivo relevance epithelial cell differentiation including highly polarized epithelium, mucus secretion, and tight membrane integrity. Additionally, we observed that the co-culture of damaged epithelial layer with the probiotics resulted in a substantial responded recovery of barrier function without bacterial overgrowth in a gut-on-a-chip. Therefore, this gut-on-a-chip could promote explorations interaction with host between microbe and provide the insights into questions of fundamental research linking the intestinal microbiome to human health and disease.

Regulatory effects of Lactobacillus plantarum HY7714 on skin health by improving intestinal condition

Despite increasing research on the gut-skin axis, there is a lack of comprehensive studies on the improvement of skin health through the regulation of the intestinal condition in humans. In this study, we investigated the benefits of Lactobacillus plantarum HY7714 (HY7714) consumption on skin health through its modulatory effects on the intestine and ensuing immune responses. HY7714 consumption led to differences in bacterial abundances from phylum to genus level, including increases in Actinobacteria followed by Bifidobacterium and a decrease in Proteobacteria. Additionally, HY7714 significantly ameliorated inflammation by reducing matrix metallopeptidases (MMP-2 and MMP-9), zonulin, and calprotectin in plasma, all of which are related to skin and intestinal permeability. Furthermore, RNA-seq analysis revealed its efficacy at restoring the integrity of the gut barrier by regulating gene expression associated with the extracellular matrix and immunity. This was evident by the upregulation of IGFBP5, SERPINE1, EFEMP1, COL6A3, and SEMA3B and downregulation of MT2A, MT1E, MT1X, MT1G, and MT1F between TNF- α and TNF- α plus HY7714 treated Caco-2 cells. These results propose the potential mechanistic role of HY7714 on skin health by the regulation of the gut condition.

P3649Analysis of clinical and angiographic parameters as predictors of recurrent vasospastic angina

Background

Patients with vasospastic angina (VA) may have recurrent chest symptoms and life-threatening arrhythmias. Despite regular medications, many VA patients experience recurrent episodes of VA. In this study, we evaluate clinical and angiographic predictors of recurrent VA.

Patients and methods

From January 2010 to May 2018, a total of 858 patients who underwent ergonovine provocation test were retrospectively reviewed. We excluded the patients who had negative results of provocation test, follow up duration less than 1 month and poor medication compliance. The recurrent-VA group consisted of patients who were re-hospitalized, visited the emergency room, or had repeated coronary angiographies because of chest pain.

Results

A total of 858 patients who underwent ergonovine provocation tests between January 2010 to May 2018 were retrospectively reviewed. Of them, 162 (mean follow-up duration, 3.0 years) were eligible for our study. The patients were divided into two groups: recurrent-VA (n=33, 20.4%) and stable-VA groups (n=129, 79.6%). Compared with the stable-VA group, the recurrent-VA group consisted mostly of men (93.9% vs. 75.2%, P=0.01), and had low LDL-cholesterol levels (93±27 mg/dl vs. 108±31 mg/dl, P=0.01). In the angiographic findings, a degree of coronary artery disease (CAD) and the site and number of spasm-positive vessels showed no difference between the two groups. Nicorandil was more frequently prescribed at discharge in the stable-VA group (15.2% vs. 35.7%, P=0.02). In the multivariate analysis, the male sex (odds ratio [OR], 5.87; 95% confidence interval [CI], 1.31–26.22; P=0.02) and non-use of nicorandil (OR, 3.51; 95% CI, 1.25–9.84; P=0.01) were the independent predictive factors in the recurrent-VA group. In the Kaplan-Meier analysis, men who did not use nicorandil (n=85, 52.5%) had higher incidences of recurrent angina compared to the other group (n=77, 47.5%). (30.6% vs. 6.6%; p<0.001).

Univariate and multivariate analysis Refractory VA (n=33) Stable VA (n=129) Odds ratio [95% CI] P value univariate Odds ratio [95% CI] P value multivariate Age <56 years, n (%) 20 (66) 58 (44) 1.88 [0.86–4.10] 0.11 NA NS Male sex, n (%) 31 (93.9) 97 (75.2) 5.11 [1.15–22.56] 0.03 5.87 [1.31–26.22] 0.02 Smoking, n (%) 17 (51.5) 46 (35.7) 1.91 [0.88–4.14] 0.09 NA NS No AMI presentation, n (%) 11 (33.3) 25 (19.4) 2.08 [0.89–4.84] 0.08 NA NS Troponin-I >0.86 ng/ml, n (%) 2 (7.1) 3 (2.7) 2.74 [0.43–17.27] 0.08 NA NS LDL-C <105 mg/dl, n (%) 21 (63) 58 (49) 1.81 [0.81–4.01] 0.14 NA NS No use of nicorandil, n (%) 5 (15.2) 46 (35.7) 3.10 [1.12–8.58] 0.02 3.51 [1.25–9.84] 0.01

Kaplan-Meier curves

Conclusions

Male sex and non-use of nicorandil were independent predictors of recurrent VA.

Brown-Sequard Syndrome after an Accidental Stab Injury of Cervical Spine: A Case Report

We report a case of Brown-Sequard syndrome (BSS) caused by an accidental stab injury of the cervical spine that shows clear magnetic resonance imaging (MRI) findings and clinical presentation. A 42-year-old woman was brought into the emergency department after a stab injury on the right side of the posterior neck from a knife that was lying in a fruit basket after slipping. The patient complained of hemiparesis of the right-side extremities, and ipsilateral hypoesthesia and contralateral sensory loss of pain and temperature were also found on neurological examination. MRI showed a signal change of the C6-7 cord level and the tract of the stab wound through the posterior neck. Irrigation and primary closure of the laceration was performed under the impression of BSS. The neurologic deficit was improved with rehabilitation therapy.

Performance of PCR-REBA assay for screening and identifying pathogens directly in whole blood of patients with suspected sepsis

AIMS

Rapid and accurate identification of a broad range of bacterial and fungal pathogens is the key to successful management of patients with bloodstream infections (BSIs). The aim of this study was to evaluate the diagnostic performance of PCR-REBA Sepsis-ID test for the detection of BSIs pathogens.

METHODS AND RESULTS

EDTA anticoagulated blood for REBA Sepsis-ID assay and blood culture samples from 882 patients with suspected sepsis were simultaneously collected from January 2014 to December 2014. Of 115 patients with positive blood culture, 64 (55·7%) were Gram-positive bacteria, 35 (30·4%) were Gram-negative bacteria, 1 (0·9%) was Candida albicans and 15 (13·0%) were polymicrobial infections. The concordance rate of blood culture system and PCR-REBA Sepsis ID test was 83·0% (95% confidence interval (CI), 79·8-84·8, P < 0·0001). Compared to blood culture, the diagnosis of bacterial proven pathogens by PCR-REBA revealed 81·0% (95% CI, 73·4-86·8, P < 0·0001) sensitivity, 83·4% (95% CI, 80·0-85·4, P < 0·0001) specificity, 80·9% positive and 95·8% negative predictive values respectively. In 10 cases with PCR-REBA positive but blood culture negative, the levels of C-reactive protein were significantly elevated 18·5 mg dl(-1) (SD ± 13·7, 95% CI 1·8-41·9) and six cases has been proven to have pathogen by bacterial 16S rRNA sequencing. Although the sensitivity for pathogen identification was not significantly different between PCR-REBA and blood culture (P = 0·5), the combination of the two methods resulted in a significantly increased rate of pathogen detection (P = 0·002). The results of this study suggested that PCR-REBA may be helpful when added to blood culture in the diagnosis and management of sepsis.

CONCLUSIONS

PCR-REBA Sepsis-ID test is a useful tool for the rapid identification of pathogenic isolates in whole blood to ensure adequate treatment for the causative agents of BSIs.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although the cost of molecular diagnostic assays is higher than the cost of conventional methods, clinical and economic cost-benefit analysis is still needed. PCR-REBA may provide essential information for accelerating therapeutic decisions to ensure effective treatment with antibiotics in the acute phase of pathogen infection.

Comparative effect of topical silicone gel and topical tretinoin cream for the prevention of hypertrophic scar and keloid formation and the improvement of scars

BACKGROUND

Numerous modalities have been used to treat keloids and hypertrophic scars; however, optimal treatment has not yet been established. Therefore, prevention is the mainstay. Recently, silicone gel and tretinoin cream have been shown to be useful for the prevention of hypertrophic scars and keloids. However, there has been no comparative study of the two topical agents thus far.

OBJECTIVE

To determine and compare the effectiveness of silicone gel and tretinoin cream for the prevention of hypertrophic scars and keloids resulting from postoperative wounds and for scar improvement.

METHOD

This study included 26 patients with 44 different wounds. The postoperative wounds were divided into two treatment groups and one control group. The patients in the first and second treatment group applied silicone gel and tretinoin cream, respectively, twice a day on their wounds after their stitches were removed. In contrast, the control group patients did not apply anything. We used the Modified Vancouver Scar Scale to quantitatively examine the effectiveness of silicone gel and tretinoin cream just after stitches removal, and at 4, 8, 12 and 24 weeks after removal of the stitches.

RESULTS

The silicone gel and tretinoin cream effectively prevented hypertrophic scars and keloids and improved scar effects in the two treatment groups compared with those in the control group. However, no significant difference was noted between the two treatment groups.

CONCLUSION

To prevent hypertrophic scars and keloids and improve scars after surgery, application of a silicone gel or a tretinoin cream to the wounds is needed.

Comparative effect of topical silicone gel and topical tretinoin cream for the prevention of hypertrophic scar and keloid formation and the improvement of scars

BACKGROUND

Numerous modalities have been used to treat keloids and hypertrophic scars; however, optimal treatment has not yet been established. Therefore, prevention is the mainstay. Recently, silicone gel and tretinoin cream have been shown to be useful for the prevention of hypertrophic scars and keloids. However, there has been no comparative study of the two topical agents thus far.

OBJECTIVE

To determine and compare the effectiveness of silicone gel and tretinoin cream for the prevention of hypertrophic scars and keloids resulting from postoperative wounds and for scar improvement.

METHOD

This study included 26 patients with 44 different wounds. The postoperative wounds were divided into two treatment groups and one control group. The patients in the first and second treatment group applied silicone gel and tretinoin cream, respectively, twice a day on their wounds after their stitches were removed. In contrast, the control group patients did not apply anything. We used the Modified Vancouver Scar Scale to quantitatively examine the effectiveness of silicone gel and tretinoin cream just after stitches removal, and at 4, 8, 12 and 24 weeks after removal of the stitches.

RESULTS

The silicone gel and tretinoin cream effectively prevented hypertrophic scars and keloids and improved scar effects in the two treatment groups compared with those in the control group. However, no significant difference was noted between the two treatment groups.

CONCLUSION

To prevent hypertrophic scars and keloids and improve scars after surgery, application of a silicone gel or a tretinoin cream to the wounds is needed.

Management of Meloidogyne incognita on tomato by root-dip treatment in culture filtrate of the blue-green alga, Microcoleus vaginatus

The nematicidal potential of culture filtrates of the blue-green alga, Microcoleus vaginatus (Cyanobacterium) was tested against Meloidogyne incognita on tomato in pots under greenhouse conditions. Prior to the transplantation of tomato seedling, roots were dipped in different concentrations (0.2%, 0.5%, 1%, 2%, 10%, 50% and 100%) of culture filtrate of M. vaginatus for 30 min. Root-dip treatment reduced the root galling and final population of M. incognita and increased vegetative growth of plants and root-mass production compared with the control. The beneficial effect of root-dip treatment increased with the increase in the concentration of culture filtrate. Root galling and final nematode populations were reduced by 65.9% and 97.5%, respectively when treated at the highest concentration.

Integration of proteomics and genomics in platelets: a profile of platelet proteins and platelet-specific genes

Platelets, while anucleate, contain RNA, some of which is translated into protein upon activation. Hypothesising that the platelet proteome is reflected in the transcriptome, we identified 82 proteins secreted from activated platelets and compared these, as well as published proteomic data, to the transcriptional profile. We also compared the transcriptome of platelets to other tissues to identify platelet-specific genes and used ontology to determine gene categories over-represented in platelets. RNA was isolated from highly pure platelet preparations for hybridization to Affymetrix oligonucleotide arrays. We identified 2,928 distinct messages as being present in platelets. The platelet transcriptome was compared with the proteome by relating both to UniGene clusters. Platelet proteomic data correlated well with the transcriptome, with 69% of secreted proteins detectable at the mRNA level, and similar concordance was obtained using two published datasets. While many of the most abundant mRNAs are for known platelet proteins, messages were detected for proteins not previously reported in platelets. Some of these may represent residual megakaryocyte messages; however, proteomic analysis confirmed the expression of many previously unreported genes in platelets. Transcripts for well-described platelet proteins are among the most platelet-specific messages. Ontological categories related to signal transduction, receptors, ion channels, and membranes are over-represented in platelets, while categories involved in protein synthesis are depleted. Despite the absence of gene transcription, the platelet proteome is mirrored in the transcriptome. Conversely, transcriptional analysis predicts the presence of novel proteins in the platelet. Transcriptional analysis is relevant to platelet biology, providing insights into platelet function and the mechanisms of platelet disorders.

Srg3, a mouse homolog of yeast SWI3, is essential for early embryogenesis and involved in brain development

Srg3 (SWI3-related gene product) is a mouse homolog of yeast SWI3, Drosophila melanogaster MOIRA (also named MOR/BAP155), and human BAF155 and is known as a core subunit of SWI/SNF complex. This complex is involved in the chromatin remodeling required for the regulation of transcriptional processes associated with development, cellular differentiation, and proliferation. We generated mice with a null mutation in the Srg3 locus to examine its function in vivo. Homozygous mutants develop in the early implantation stage but undergo rapid degeneration thereafter. An in vitro outgrowth study revealed that mutant blastocysts hatch, adhere, and form a layer of trophoblast giant cells, but the inner cell mass degenerates after prolonged culture. Interestingly, about 20% of heterozygous mutant embryos display defects in brain development with abnormal organization of the brain, a condition known as exencephaly. Histological examination suggests that exencephaly is caused by the failure in neural fold elevation, resulting in severe brain malformation. Our findings demonstrate that Srg3 is essential for early embryogenesis and plays an important role in the brain development of mice.

Epidemiologic and clinical survey of Behcet's disease in Korea: the first multicenter study

The prevalence of Behcet's disease is the highest in the East Asian and the Mediterranean countries. Behcet's disease is also distributed in the Asian countries, but the nationwide survey has not been performed in Korea yet. The Korean Study Group for Behcet's Disease, founded in 1999, conducted a multicenter, retrospective survey on epidemiologic and clinical features of the patients with Behcet's disease from 20 hospitals around the nation from 1997 to 1999. Of 3,497 patients, 1,527 were classified into complete or incomplete type of Behcet's disease according to the revised Shimizu's classification. The sex ratio was 1:1.75 with the female predominance. Geographical distribution showed the highest frequency in Seoul (38.5%). Clinically, 98.8% had oral ulcers, 83.2% had genital ulcers, 84.3% had skin lesions and 50.9% had ocular lesions. As for the minor clinical manifestations, articular symptoms were the most frequent. The pathergy test showed positive in 15.4% of patients and revealed a higher positive rate in males (20.2%) than in females (12.7%). In conclusion, we performed the first multicenter study on Behcet's disease in Korea and revealed the female predominance, higher frequency of ocular lesions, and lower positivity of pathergy test in the patients.

Notch1 confers a resistance to glucocorticoid-induced apoptosis on developing thymocytes by down-regulating SRG3 expression

We previously have reported that SRG3 is required for glucocorticoid (GC)-induced apoptosis in the S49.1 thymoma cell line. Activation of Notch1 was shown to induce GC resistance in thymocytes. However, the specific downstream target of Notch1 that confers GC resistance on thymocytes is currently unknown. We found that the expression level of SRG3 was critical in determining GC sensitivity in developing thymocytes. The expression of SRG3 also was down-regulated by the activated form of Notch1 (NotchIC). The promoter activity of the SRG3 gene also was down-regulated by NotchIC. Expression of transgenic SRG3 resulted in the restoration of GC sensitivity in thymocytes expressing transgenic Notch1. These results suggest that SRG3 is the downstream target of Notch1 in regulating GC sensitivity of thymocytes.

Peripheral T cells become sensitive to glucocorticoid- and stress-induced apoptosis in transgenic mice overexpressing SRG3

Immature double-positive thymocytes are sensitive to glucocorticoid (GC)-induced apoptosis, whereas mature single-positive T cells are relatively resistant. Thymocytes seem to acquire resistance to GCs during differentiation into mature single-positive thymocytes. However, detailed knowledge concerning what determines the sensitivity of thymocytes to GCs and how GC sensitivity is regulated in thymocytes during development is lacking. We have previously reported that the murine SRG3 gene (for SWI3-related gene) is required for GC-induced apoptosis in a thymoma cell line. Herein, we provide results suggesting that the expression level of SRG3 protein determines the GC sensitivity of T cells in mice. SRG3 associates with the GC receptor in the thymus, but rarely in the periphery. Transgenic overexpression of the SRG3 protein in peripheral T cells induces the formation of the complex and renders the cells sensitive to GC-induced apoptosis. Our results also show that blocking the formation of the SRG3-GC receptor complex with a dominant negative mutant form of SRG3 decreases GC sensitivity in thymoma cells. In addition, mice overexpressing the SRG3 protein appear to be much more susceptible to stress-induced deletion of peripheral T cells than normal mice, which may result in an immunosuppressive state in an animal.

8-Cl-cAMP induces cell cycle-specific apoptosis in human cancer cells

8-Cl-cyclic adenosine monophosphate (8-Cl-cAMP) has been known to induce growth inhibition and differentiation in a variety of cancer cells by differential modulation of protein kinase A isozymes. To understand the anticancer activity of 8-Cl-cAMP further, we investigated the effect of 8-Cl-cAMP on apoptosis in human cancer cells. Most of the tested human cancer cells exhibited apoptosis upon treatment with 8-Cl-cAMP, albeit with different sensitivity. Among them, SH-SY5Y neuroblastoma cells and HL60 leukemic cells showed the most extensive apoptosis. The effect of 8-Cl-cAMP was not reproduced by other cAMP analogues or cAMP-elevating agents, showing that the effect of 8-Cl-cAMP was not caused by simple activation of protein kinase A (PKA). However, competition experiments showed that the binding of 8-Cl-cAMP to the cAMP receptor was essential for the induction of apoptosis. After the treatment of 8-Cl-cAMP, cells initially accumulated at the S and G2/M phases of the cell cycle and then apoptosis began to occur among the population of cells at the S/G2/M cell cycle phases, indicating that the 8-Cl-cAMP-induced apoptosis is closely related to cell cycle control. In support of this assumption, 8-Cl-cAMP-induced apoptosis was blocked by concomitant treatment with mimosine, which blocks the cell cycle at early S phase. Interestingly, 8-Cl-cAMP did not induce apoptosis in primary cultured normal cells and non-transformed cell lines, showing that 8-Cl-cAMP-induced apoptosis is specific to transformed cells. Taken together, our results show that the induction of apoptosis is one of the mechanisms through which 8-Cl-cAMP exerts anticancer activity.

Progesterone together with estrogen attenuates homologous upregulation of gonadotropin-releasing hormone receptor mRNA in primary cultured rat pituitary cells

In a previous study, we clearly demonstrated that an application of gonadotropin-releasing hormone (GnRH) to cultured rat pituitary cells increased the expression of GnRH receptor (GnRH-R) mRNA through transcriptional activation of GnRH-R gene rather than suppression of the turnover rate of GnRH-R mRNA. Along with GnRH, gonadal steroids seem to be an important regulator for GnRH-R expression in the pituitary gland. Recent in vivo studies reported that an application of gonadal steroids to gonadectomized animals modulated GnRH-R mRNA expression in the pituitary gland. However, it has not been clearly understood whether steroids may act directly at the pituitary or indirectly via modulation of hypothalamic GnRH release. Therefore, we assessed the effects of estrogen and progesterone on GnRH-R mRNA expression in primary cultured female rat pituitary cells. Neither estradiol nor progesterone modulates the basal expression of GnRH-R mRNA in primary cultured pituitary cells. When cultured pituitary cells were exposed to different doses of estradiol in combination with GnRH (0.2 nM), the GnRH-stimulated increment of GnRH-R mRNA expression was not significantly changed by estradiol at any given doses. However, when different doses of progesterone were added to primary cultured pituitary cells in combination with GnRH (0.2 nM), GnRH-induced increases in GnRH-R mRNA levels were reduced in a dose-related manner, showing a significant reduction at 100 nM progesterone. Furthermore, the addition of estradiol reinforced the suppressive effect of progesterone on the homologous upregulation of GnRH-R mRNA expression. Collectively, our results clearly demonstrated that progesterone directly attenuates the homologous upregulation of GnRH-R mRNA expression at the pituitary level, and that estradiol potentiates the effect of progesterone.

Gain- and loss-of-function of Rhp51, a Rad51 homolog in fission yeast, reveals dissimilarities in chromosome integrity

Rad51 is crucial not only in homologous recombination and recombinational repair but also in normal cellular growth. To address the role of Rad51 in normal cell growth we investigated morphological changes of cells after overexpression of wild-type and a dominant negative form of Rad51 in fission yeast. Rhp51, a Rad51 homolog in Schizosaccharomyces pombe, has a highly conserved ATP-binding motif. Rhp51 K155A, which has a single substitution in this motif, failed to rescue hypersensitivity of a rhp51 mutant to methyl methanesulfonate (MMS) and UV, whereas it binds normally to Rhp51 and Rad22, a Rad52 homolog. Two distinct cellular phenotypes were observed when Rhp51 or Rhp51 K155A was overexpressed in normal cells. Overexpression of Rhp51 caused lethality in the absence of DNA-damaging agents, with acquisition of a cell cycle mutant phenotype and accumulation of a 1C DNA population. On the other hand, overexpression of Rhp51 K155A led to a delay in G(2) with decondensed nuclei, which resembled the phenotype of rhp51. The latter also exhibited MMS and UV sensitivity, indicating that Rhp51 K155A has a dominant negative effect. These results suggest an association between DNA replication and Rad51 function.

Functional genomic, biochemical, and genetic characterization of the Salmonella pduO gene, an ATP:cob(I)alamin adenosyltransferase gene

Salmonella enterica degrades 1,2-propanediol by a pathway dependent on coenzyme B12 (adenosylcobalamin [AdoCb1]). Previous studies showed that 1,2-propanediol utilization (pdu) genes include those for the conversion of inactive cobalamins, such as vitamin B12, to AdoCbl. However, the specific genes involved were not identified. Here we show that the pduO gene encodes a protein with ATP:cob(I)alamin adenosyltransferase activity. The main role of this protein is apparently the conversion of inactive cobalamins to AdoCbl for 1,2-propanediol degradation. Genetic tests showed that the function of the pduO gene was partially replaced by the cobA gene (a known ATP:corrinoid adenosyltransferase) but that optimal growth of S. enterica on 1,2-propanediol required a functional pduO gene. Growth studies showed that cobA pduO double mutants were unable to grow on 1,2-propanediol minimal medium supplemented with vitamin B(12) but were capable of growth on similar medium supplemented with AdoCbl. The pduO gene was cloned into a T7 expression vector. The PduO protein was overexpressed, partially purified, and, using an improved assay procedure, shown to have cob(I)alamin adenosyltransferase activity. Analysis of the genomic context of genes encoding PduO and related proteins indicated that particular adenosyltransferases tend to be specialized for particular AdoCbl-dependent enzymes or for the de novo synthesis of AdoCbl. Such analyses also indicated that PduO is a bifunctional enzyme. The possibility that genes of unknown function proximal to adenosyltransferase homologues represent previously unidentified AdoCbl-dependent enzymes is discussed.

Rdp1, a novel zinc finger protein, regulates the DNA damage response of rhp51(+) from Schizosaccharomyces pombe

The Schizosaccharomyces pombe DNA repair gene rhp51(+) encodes a RecA-like protein with the DNA-dependent ATPase activity required for homologous recombination. The level of the rhp51(+) transcript is increased by a variety of DNA-damaging agents. Its promoter has two cis-acting DNA damage-responsive elements (DREs) responsible for DNA damage inducibility. Here we report identification of Rdp1, which regulates rhp51(+) expression through the DRE of rhp51(+). The protein contains a zinc finger and a polyalanine tract similar to ones previously implicated in DNA binding and transactivation or repression, respectively. In vitro footprinting and competitive binding assays indicate that the core consensus sequences (NGG/TTG/A) of DRE are crucial for the binding of Rdp1. Mutations of both DRE1 and DRE2 affected the damage-induced expression of rhp51(+), indicating that both DREs are required for transcriptional activation. In addition, mutations in the DREs significantly reduced survival rates after exposure to DNA-damaging agents, demonstrating that the damage response of rhp51(+) enhances the cellular repair capacity. Surprisingly, haploid cells containing a complete rdp1 deletion could not be recovered, indicating that rdp1(+) is essential for cell viability and implying the existence of other target genes. Furthermore, the DNA damage-dependent expression of rhp51(+) was significantly reduced in checkpoint mutants, raising the possibility that Rdp1 may mediate damage checkpoint-dependent transcription of rhp51(+).

Progesterone together with estrogen attenuates homologous upregulation of gonadotropin-releasing hormone receptor mRNA in primary cultured rat pituitary cells

In a previous study, we clearly demonstrated that an application of gonadotropin-releasing hormone (GnRH) to cultured rat pituitary cells increased the expression of GnRH receptor (GnRH-R) mRNA through transcriptional activation of GnRH-R gene rather than suppression of the turnover rate of GnRH-R mRNA. Along with GnRH, gonadal steroids seem to be an important regulator for GnRH-R expression in the pituitary gland. Recent in vivo studies reported that an application of gonadal steroids to gonadectomized animals modulated GnRH-R mRNA expression in the pituitary gland. However, it has not been clearly understood whether steroids may act directly at the pituitary or indirectly via modulation of hypothalamic GnRH release. Therefore, we assessed the effects of estrogen and progesterone on GnRH-R mRNA expression in primary cultured female rat pituitary cells. Neither estradiol nor progesterone modulates the basal expression of GnRH-R mRNA in primary cultured pituitary cells. When cultured pituitary cells were exposed to different doses of estradiol in combination with GnRH (0.2 nM), the GnRH-stimulated increment of GnRH-R mRNA expression was not significantly changed by estradiol at any given doses. However, when different doses of progesterone were added to primary cultured pituitary cells in combination with GnRH (0.2 nM), GnRH-induced increases in GnRH-R mRNA levels were reduced in a dose-related manner, showing a significant reduction at 100 nM progesterone. Furthermore, the addition of estradiol reinforced the suppressive effect of progesterone on the homologous upregulation of GnRH-R mRNA expression. Collectively, our results clearly demonstrated that progesterone directly attenuates the homologous upregulation of GnRH-R mRNA expression at the pituitary level, and that estradiol potentiates the effect of progesterone.

Identification of Rab6 as an N-ethylmaleimide-sensitive fusion protein-binding protein

In this study we show the interaction of N-ethylmaleimide-sensitive fusion protein (NSF) with a small GTP-binding protein, Rab6. NSF is an ATPase involved in the vesicular transport within eukaryotic cells. Using the yeast two-hybrid system, we have isolated new NSF-binding proteins from the rat lung cDNA library. One of them was Rab6, which is involved in the vesicular transport within the Golgi and trans-Golgi network as a Ras-like GTPase. We demonstrated that the N-terminal domain of NSF interacted with the C-terminal domain of Rab6, and these proteins were co-immunoprecipitated from the rat brain extract. This interaction was maintained preferentially in the presence of hydrolysable ATP. Recombinant NSF-His(6) can also bind to C-terminal Rab6-glutathione S-transferase under the conditions to allow the ATP hydrolysis. Surprisingly, Rab6 stimulates the ATPase activity of NSF by approx. 2-fold as does alpha-soluble NSF attachment protein receptor. Anti-Rab6 polyclonal antibodies significantly inhibited the Rab6-stimulated ATPase activity of NSF. Furthermore, we found that Rab3 and Rab4 can also associate with NSF and stimulate its ATPase activity. Taken together, we propose a model in which Rab can form an ATP hydrolysis-regulated complex with NSF, and function as a signalling molecule to deliver the signal of vesicle fusion through the interaction with NSF.

Rad22 protein, a rad52 homologue in Schizosaccharomyces pombe, binds to DNA double-strand breaks

DNA double-strand breaks can be introduced by exogenous agents or during normal cellular processes. Genes belonging to the RAD52 epistasis group are known to repair these breaks in budding yeast. Among these genes, RAD52 plays a central role in homologous recombination and DNA double-strand break repair. Despite its importance, its mechanism of action is not yet clear. It is known, however, that the human homologue of Rad52 is capable of binding to DNA ends in vitro. Herein, we show that Rad22 protein, a Rad52 homologue in the fission yeast Schizosaccharomyces pombe, can similarly bind to DNA ends at double-strand breaks. This end-binding ability was demonstrated in vitro by electron microscopy and by protection from exonuclease attack. We also showed that Rad22 specifically binds near double-strand break associated with mating type switching in vivo by chromatin immunoprecipitation analysis. This is the first evidence that a recombinational protein directly binds to DNA double-strand breaks in vivo.

An ikaros-containing chromatin-remodeling complex in adult-type erythroid cells

We have previously described a SWI/SNF-related protein complex (PYR complex) that is restricted to definitive (adult-type) hematopoietic cells and that specifically binds DNA sequences containing long stretches of pyrimidines. Deletion of an intergenic DNA-binding site for this complex from a human beta-globin locus construct results in delayed human gamma- to beta-globin switching in transgenic mice, suggesting that the PYR complex acts to facilitate the switch. We now show that PYR complex DNA-binding activity also copurifies with subunits of a second type of chromatin-remodeling complex, nucleosome-remodeling deacetylase (NuRD), that has been shown to have both nucleosome-remodeling and histone deacetylase activities. Gel supershift assays using antibodies to the ATPase-helicase subunit of the NuRD complex, Mi-2 (CHD4), confirm that Mi-2 is a component of the PYR complex. In addition, we show that the hematopoietic cell-restricted zinc finger protein Ikaros copurifies with PYR complex DNA-binding activity and that antibodies to Ikaros also supershift the complex. We also show that NuRD and SWI/SNF components coimmunopurify with each other as well as with Ikaros. Competition gel shift experiments using partially purified PYR complex and recombinant Ikaros protein indicate that Ikaros functions as a DNA-binding subunit of the PYR complex. Our results suggest that Ikaros targets two types of chromatin-remodeling factors-activators (SWI/SNF) and repressors (NuRD)-in a single complex (PYR complex) to the beta-globin locus in adult erythroid cells. At the time of the switch from fetal to adult globin production, the PYR complex is assembled and may function to repress gamma-globin gene expression and facilitate gamma- to beta-globin switching.

The stress-activated MAP kinase Sty1/Spc1 and a 3'-regulatory element mediate UV-induced expression of the uvi15(+) gene at the post-transcriptional level

Exposure of Schizosaccharomyces pombe cells to UV light results in increased uvi15(+) gene expression at both the mRNA and protein levels, leading to elevated cell survival. This UV-induced expression of the uvi15(+) gene was reduced in Deltasty1 and Deltawis1 cells lacking the stress-activated protein kinase pathway, but not in DNA damage checkpoint mutants. To further understand the cellular mechanisms responsible for this UV-induced expression, the transcription rate and mRNA half-life were investigated. Transcription run-on assays revealed that the rate of uvi15(+) transcription was increased 1.8-fold regardless of Sty1 when cells were UV irradiated. The half-life of uvi15(+) mRNA was also increased 1.5-fold after UV irradiation, but it was decreased in the Deltasty1 background for both basal and UV-induced mRNAs, indicating that the stress-activated MAPK cascade can mediate UV-induced gene expression by increasing mRNA half-life. Deletion analyses identified a 54 nt element downstream of the distal poly(A) site, which was involved in the increased half-life of uvi15(+) mRNA. These results suggest that both Sty1 and the 3'-regulatory element regulate UV-induced expression of the uvi15(+) gene at the post-transcriptional level.

Improvement of oxidative stability of conjugated linoleic acid (CLA) by microencapsulation in cyclodextrins

Oxidative stability of conjugated linoleic acid (CLA) encapsulated in alpha-, beta-, and gamma-cyclodextrins (designated CLA/CDs microencapsules) was studied by measuring the headspace-oxygen depletion in airtight serum bottles and by measuring the peroxide values (POV). The rate of oxygen depletion was reduced from 41.0 (control) to 21.5, 2.1, 1.2, and 1.1 micromol/L.h(-)(1) by CLA/alpha-CD microencapsules at 1:1, 1:2, 1:4, and 1:6 mole ratios, respectively, indicating that CLA oxidation was completely protected by a 1:4 mole ratio of CLA/alpha-CD. Such a protective effect by CLA/beta-CD or CLA/gamma-CD microencapsules was achieved at a 1:6 mole ratio, but the effect by CLA/beta-CD was slightly greater than that by CLA/gamma-CD. The protective effect of alpha-, beta-, and gamma-CDs for CLA oxidation was confirmed by their POV-reducing abilities in CLA/CDs. These results suggest that alpha-CD was the most effective for the protection of CLA oxidation by microencapsulation, followed by beta-CD and gamma-CD.

Homologous upregulation of gonadotropin-releasing hormone receptor mRNA occurs through transcriptional activation rather than modulation of mRNA stability

In a previous study, we showed that even continuous application of gonadotropin-releasing hormone (GnRH) could increase the steady-state levels of GnRH receptor (GnRH-R) mRNA if treated for a relatively short period (6 h). Therefore, in the present study we examined whether GnRH-induced increment of GnRH-R mRNA is owing to stabilization of the preexisting GnRH-R mRNA or new synthesis of GnRH-R mRNA or both. Initially, to examine the effect on new RNA synthesis, the transcription inhibitor, actinomycin D (2 microM), was added to primary cultured rat anterior pituitary cells. In the presence of transcription inhibitor, GnRH-induced augmentation of GnRH-R mRNA levels was completely abolished. This result indicates that homologous upregulation of GnRH-R mRNA expression occurs at least through new RNA synthesis of GnRH-R gene. We further assessed the effects of GnRH on the turnover rate of GnRH-R mRNA using actinomycin D (2 microM). The basal half-life of GnRH-R mRNA was estimated to be approx 21 h. The application of GnRH tended to slightly suppress the basal turnover rate of GnRH; however, there was no statistically significant difference, compared with the group treated with actinomycin D alone. Collectively, our results suggest that the homologous upregulation of GnRH-R mRNA may occur through transcriptional activation of GnRH-R gene rather than enhancement of GnRH-R mRNA stability, although we did not examine the transcription rate of GnRH-R gene.

Dual anticancer activity of 8-Cl-cAMP: inhibition of cell proliferation and induction of apoptotic cell death

8-Cl-cAMP induces apoptotic cell death in human cancer cells. To look at this more closely, we examined the changes in the levels of Bcl-2 family proteins during 8-Cl-cAMP-induced apoptosis of SH-SY5Y human neuroblastoma cells. Following the treatment with 8-Cl-cAMP, Bcl-2 was transiently down-regulated and Bad was increased continuously up to day 5. In addition, overexpression of Bcl-2 efficiently blocked the 8-Cl-cAMP-induced apoptosis, suggesting Bcl-2 family proteins may be involved in the 8-Cl-cAMP-induced apoptosis. The contribution of the apoptotic cell death and the inhibition of cell proliferation in the 8-Cl-cAMP-induced growth inhibition was closely monitored in the Bcl-2-overexpressing cells. Though the apoptosis was reduced significantly, no significant difference was observed in the inhibition of cell proliferation up to day 2 of 8-Cl-cAMP treatment. These results suggest that 8-Cl-cAMP exerts anticancer activity by two distinct mechanisms, i.e. , through the inhibition of cell proliferation as well as the induction of apoptosis. Supporting this notion was the observations that (1) suppression of apoptosis by zVAD did not abrogate 8-Cl-cAMP-induced inhibition of cell proliferation, and (2) 8-Cl-cAMP did not show additive inhibition of cell proliferation in RIIbeta-overexpressing cells.

Clinical features of 31 patients with systemic contact dermatitis due to the ingestion of Rhus (lacquer)

In Korea, Rhus has been used as a folk medicine to cure gastrointestinal diseases and as a health food. We review the clinicopathological and laboratory findings in patients with systemic contact dermatitis caused by intake of Rhus. We reviewed medical records and histopathological sections from 31 patients during a 10-year period. The male/female ratio was 1.4: 1 and the average age was 43.8 years (range 22-70). Ten patients (32%) had a known history of allergy to lacquer. Rhus was ingested to treat gastrointestinal problems including indigestion and gastritis (45%), and as a health food (39%), in cooked meat, in herbal medicine, or taken by inhalation. The patients developed skin lesions such as a maculopapular eruption (65%), erythema multiforme (EM, 32%), erythroderma (19%), pustules, purpura, weals and blisters. Erythroderma was very frequent in patients with a known history of allergy to lacquer, but maculopapular and EM-type eruptions were more frequently observed in those without a history of allergy. All patients experienced generalized or localized pruritus. Other symptoms included gastrointestinal problems (32%), fever (26%), chills and headache; many developed leucocytosis (70%) with neutrophilia (88%), while some showed toxic effects on liver and kidney. Fifty-nine per cent of patients observed cutaneous or general symptoms within a day after ingestion of Rhus. There was no difference in the time lag for symptoms to develop between patients allergic and not allergic to Rhus. All patients responded well to treatment with systemic steroids and antihistamines. Common histopathological findings were vascular dilatation, perivascular lymphohistiocytic infiltration, and extravasation of red blood cells in the upper dermis. Rhus lacquer should not be ingested in view of its highly allergic and toxic effects.

Fission yeast hrp1, a chromodomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation

Hrp1 of Schizosaccharomyces pombe is a member of the CHD protein family, characterized by a chromodomain, a Myb-like telobox-related DNA-binding domain and a SNF2-related helicase/ATPase domain. CHD proteins are thought to be required for modification of the chromatin structure in transcription, but the exact roles of CHD proteins are not known. Here we examine the sub-cellular localization and biochemical activity of Hrp1 and the phenotypes of hrp1 Delta and Hrp1-overexpressing strains. Fluorescence microscopy revealed that Hrp1 protein is targeted to the nucleus. We found that Hrp1 exhibited DNA-dependent ATPase activity, stimulated by both single- and double-stranded DNA. Overexpression of Hrp1 caused slow cell growth accompanied by defective chromosome condensation in anaphase resulting in a 'cut' (celluntimelytorn) phenotype and chromosome loss. The hrp1 Delta mutation also caused abnormal anaphase and mini-chromosome loss phenotypes. Electron micrographs demonstrated that aberrantly shaped nucleoli appeared in Hrp1-overexpressing cells. Therefore, these results suggest that Hrp1 may play a role in mitotic chromosome segregation and maintenance of chromatin structure by utilizing the energy from ATP hydrolysis.

Participation of type II protein kinase A in the retinoic acid-induced growth inhibition of SH-SY5Y human neuroblastoma cells

To examine the role of protein kinase A (EC 2.7.1.37) isozymes in the retinoic acid-induced growth inhibition and neuronal differentiation, we investigated the changes of protein kinase A isozyme patterns in retinoic acid-treated SH-SY5Y human neuroblastoma cells. Retinoic acid induced growth inhibition and neuronal differentiation of SH-SY5Y cells in a dose- and time-dependent manner. Neuronal differentiation was evidenced by extensive neurite outgrowth, decrease of N-Myc oncoprotein, and increase of GAP-43 mRNA. Type II protein kinase A activity increased by 1.5-fold in differentiated SH-SY5Y cells by retinoic acid treatment. The increase of type II protein kinase A was due to the increase of RIIbeta and Calpha subunits. Since type II protein kinase A and RIIbeta have been known to play important role(s) in the growth inhibition and differentiation of cancer cells, we further investigated the role of the increased type II protein kinase A by overexpressing RIIbeta in SH-SY5Y cells. The growth of RIIbeta-overexpressing cells was slower than that of parental cells, being comparable to that of retinoic acid-treated cells. Retinoic acid treatment further increased the RIIbeta level and further inhibited the growth of RIIbeta-overexpressing cells, showing strong correlation between the level of RIIbeta and growth inhibition. However, RIIbeta-overexpressing cells did not show any sign of neuronal differentiation and responded to retinoic acid in the same way as parental cells. These data suggest that protein kinase A participates in the retinoic acid-induced growth inhibition through the up-regulation of RIIbeta/type II protein kinase A.

Sp1 mediates cell proliferation-dependent regulation of rat DNA topoisomerase IIalpha gene promoter

DNA topoisomerase IIalpha (topo IIalpha) is an essential nuclear enzyme required for chromosome segregation during mitosis. Consistent with its critical role in cell division is the fact that the expression of the gene for topo IIalpha is strongly regulated by the proliferation state of cells. Using a transient expression system, we determined the contribution of putative cis-acting elements in its promoter region to its basal level and cell proliferation-dependent transcription. Experiments with 5' and/or 3' serial deletion and site-directed mutation revealed that (1) maximal promoter activity resides in the fragment extending to position -663 bp from the ATG initiation codon, (2) minimal promoter activity is harboured at -195 bp, (3) the defined minimal promoter contains only two putative elements, inverted CCAAT box 4 (ICB4) (-166 to -162 bp) and the most proximal GC-rich box in the promoter (GC2) (-149 to -143 bp), and (4) ICB4 is most important in the basal-level transcription of the gene for rat topo IIalpha. The luciferase activities of the mutated reporter plasmids in G(0)-arrested and exponentially growing cells showed that proliferation-specific regulation is controlled mainly by GC2. Electrophoretic mobility-shift assays indicated that Sp1 binds specifically to the GC2 site. The extent of DNA-protein complex formation increases after the stimulation of cells to proliferate. These results indicate that the increased binding activity of Sp1 to GC2 is important in the up-regulation of the gene for topo IIalpha in growing cells.

A microsatellite survey of cattle from a centre of origin: the Near East

Eight humpless cattle breeds from the Near East, three from Europe, one from West Africa and two zebu breeds from India were screened with 20 microsatellite loci. Breeds from the Near East revealed considerable levels of introgression from zebu cattle, which was apparent most in populations from the East and which declined in populations further West. This nonrandom pattern is suggestive of the introduction of zebu cattle from the East. Notwithstanding the overlay of zebu alleles, it was possible to demonstrate that Near Eastern cattle exhibited significantly higher levels of allelic diversity than breeds from other regions, which is consistent with the view that this region represents a primary domestication centre for Bos taurus cattle. The hypothesis that B. taurus and B. indicus cattle have separate domestic origins is also supported by the survey, a large genetic divergence being apparent between the nonhybrid taurine and zebu groups.

Homologous upregulation of GnRH receptor mRNA by continuous GnRH in cultured rat pituitary cells

The present study examined the effects of continuous treatment with gonadotropin-releasing hormone (GnRH) on GnRH receptor (GnRH-R) mRNA levels in dispersed cultures of rat pituitary cells. Pituitary GnRH-R mRNA levels were determined by competitive reverse transcriptase polymerase chain reaction. When pituitary cells were continuously exposed to a low dose of GnRH (0.2 nM), GnRH-R mRNA levels were transiently increased. The levels of GnRH-R mRNA were significantly increased up to 6 h and diminished to untreated levels by 24 h. Luteinizing hormone (LH) release was also increased significantly up to 12 h, maintaining similar levels in LH release thereafter. When GnRH antagonist ([D-pGlu1, D-Phe2, D-Trp3,6]-LH-RH) was added to the cultures together with GnRH (0.2 nM) for 6 h, the stimulatory effect of GnRH on GnRH-R mRNA levels and LH release was significantly diminished in a dose-related manner. In another experiment, pituitary cells were treated with various doses of GnRH (0.02-200 nM) for a relatively short (6 h) or a longer (24 h) period. When pituitary cells were exposed for 6 h, all doses of GnRH (0.02-200 nM) significantly increased GnRH-R mRNA levels in a dose-dependent manner. By contrast, continuous exposure to GnRH for 24 h was ineffective in changing pituitary GnRH-R mRNA levels at any given doses. These results indicate that the duration of GnRH treatment is critical for upregulation of GnRH-R mRNA by continuous GnRH. When pituitary cells were treated for 6 h with either a continuous mode of GnRH (0.2 nM) or an hourly pulsatile mode of GnRH (0.2 nM, 6 min/h), both treatments significantly augmented GnRH-R mRNA levels. Thus, the modes of GnRH application, if treated for a relatively short period, do not appear to make a significant difference in upregulation of GnRH-R mRNA levels. Collectively, our data provide strong evidence that continuous GnRH application is able to upregulate pituitary GnRH-R mRNA levels, if treated for a relatively short period (6 h).

Ala99ser mutation in RI alpha regulatory subunit of protein kinase A causes reduced kinase activation by cAMP and arrest of hormone-dependent breast cancer cell growth

Expression of the RIalpha regulatory subunit of protein kinase A type I is increased in human cancer cell lines, in primary tumors, in cells after transformation, and in cells upon stimulation of growth. Ala99 (the pseudophosphorylation site) of human RIalpha was replaced with Ser (RIalpha-p) for the structure-function analysis of RIalpha. MCF-7 hormone-dependent breast cancer cells were transfected with an expression vector for the wild-type RIalpha or mutant RIalpha-p. Overexpression of RIalpha-P resulted in suppression of protein kinase A type II, the isozyme of type I kinase, production of kinase exhibiting reduced cAMP activation, and inhibition of cell growth showing an increase in G0/G1 phase of the cell cycle and apoptosis. The wild-type RIalpha overexpression had no effect on protein kinase A isozyme distribution or cell growth. Overexpression of protein kinase A type II regulatory subunit, RIIbeta, suppressed RIalpha and protein kinase A type I and inhibited cell growth. These results show that the growth of hormone-dependent breast cancer cells is dependent on the functional protein kinase A type I.

Isolation of developmentally regulated novel genes based on sequence identity and gene expression pattern

Based on the surmise that a variety of genes might play important roles in embryonic development and tissue differentiation, and that some of them are likely to be expressed in undifferentiated ES cells, we attempted to identify new genes from the ES cell cDNA library. The modified method of expressed sequence tags (ESTs) and the examination of the expression patterns in adult tissues and in vitro differentiated ES cells were utilized in this study. We have isolated and identified several novel cDNA clones with interesting developmental expression pattern. Among the 83 clones randomly chosen, 23 clones (27.7%) have no homology to any sequences in public databases. The rest contain limited or complete sequence homology to the previously reported mammalian genes or ESTs, yet some clones have not been previously identified in the mouse. To examine the expression profile of clones during development and differentiation, sets of slot blots were hybridized with developmental stage specific or tissue specific probes. Out of 40 novel clones tested (21 totally unknown clones and 19 unidentified clones in mouse), most of them were up- or down-regulated as differentiation proceeded, and some clones showed differentiation-stage specific expression profiles. Surprisingly, a majority of genes were also expressed in adult tissues, and some clones even revealed tissue specific expression. These results demonstrate that not only was the strategy we employed in this study quite efficient for screening novel genes, but that the information gained by such studies would also be a useful guide for further analysis of these genes. It also suggests the feasibility of this approach to explore the genomewide network of gene expression during complicated biological processes, such as embryonic development and tissue differentiation.

Characterization of a novel mouse cDNA, ES18, involved in apoptotic cell death of T-cells

Using the modified screening approach in combination with expressed sequence tags, we have identified several novel cDNAs from mouse embryonic stem (ES) cells, whose expression is tissue-restricted and/or developmentally regulated. One of the cDNAs, ES18, is preferentially expressed in lymph node and thymus, and contains noteworthy features of transcriptional regulator. The expression of ES18 transcript was selectively regulated during the apoptosis of T-cell thymoma S49.1 induced by several stimuli. Interestingly, the ES18 transcript was differently regulated in the mutually antagonistic process, between dexamethasone- and A23187-induced cell death of T-cells. Moreover, the message level of ES18 was selectively enhanced by staurosporine, a broad protein kinase inhibitor, but not by other protein kinase inhibitors such as GF109203X and H89. In addition, ES18 transcript was induced by C2-ceramide, which is a mediator of both dexamethasone- and staurosporine-induced apoptotic signaling. We further showed that transient overexpression of ES18 in mouse T-cell lymphoma increased the apoptotic cell death. These data suggest that ES18 may be selectively involved in specific apoptotic processes in mouse T-cells.

Two sinusoidal heart rate patterns in fetal lambs undergoing extracorporeal membrane oxygenation

OBJECTIVES

The study analyzed the phase relationship between fetal heart rate and arterial blood pressure fluctuation during sinusoidal heart rate patterns in fetal lambs.

STUDY DESIGN

Thirty-two fetal lambs were placed on extracorporeal membrane oxygenation after cesarean delivery at ages ranging between 113 and 133 days' gestation. Sinusoidal heart rate patterns persisting for >10 minutes were analyzed. The relationships between the sinusoidal heart rate cycles and the arterial blood pressure cycles were quantitatively expressed in degrees by timing the zenith and the nadir of each and assigning a phase-angle index (with 0 [360] and 180 degrees being synchronized and reciprocal, respectively). Simultaneous blood samples were taken from the 4 different sites of the fetal circulation for blood gas and acid-base analysis when the sinusoidal heart rate pattern appeared. Regional cerebral blood flow was determined by means of the colored microsphere technique in 8 fetuses with sinusoidal patterns and 7 control fetuses.

RESULTS

Sinusoidal heart rate patterns were observed in 13 (40.6%) of the 32 fetal lambs. Two types of fetal heart rate and arterial blood pressure relationship could be recognized during sinusoidal pattern, the reciprocal type (n = 7) and the synchronized type (n = 9). A reciprocal type of sinusoidal pattern preceded a synchronized type pattern in 3 lambs that showed sinusoidal patterns at different stages of the experiment. The reciprocal type was associated with a higher baseline heart rate and amplitude of the sinusoidal heart rate pattern than was the synchronized type. The synchronized type was associated with a lower pH and base excess than was the reciprocal type. The cerebral blood flow in the medulla oblongata was significantly lower during the synchronized type pattern than during the reciprocal type pattern.

CONCLUSION

There are 2 types of sinusoidal heart rate pattern. A synchronized type sinusoidal heart rate pattern may indicate more advanced fetal compromise than is associated with a reciprocal type pattern.

Synthesis and biological activity of KCB-328 and its analogues: novel class III antiarrhythmic agents with little reverse frequency dependence

A series of 3,4-dimethoxyphenethylamine derivatives was prepared, and their prolongation effects on effective refractory period of contractile response (ERPc) and action potential duration (APD) in isolated guinea-pig papillary muscles at 1 Hz and 3 Hz were examined. SAR studies led to the identification of KCB-328 (51) which is a novel class III antiarrhythmic agent with little reverse frequency dependence.

Two species of mRNAs for the fyn proto-oncogene are produced by an alternative polyadenylation

Two mRNA species with different sizes (3.8 kb and 2.8 kb) for the fyn proto-oncogene have been noticed during Northern hybridization analysis. However, the difference between the two mRNA species has not been resolved yet. By screening a phage expression library using the monoclonal antibody (mAb) B16-5 which recognizes Src homology 3 (SH3) domains of phospholipase C-gamma and Nck, we have cloned a cDNA encoding the larger species of fyn mRNA. The size of the clone was 3.5 kb and DNA sequencing analysis of the clone showed that it was fyn expressed mainly in T-cells, fyn (T), with an untranslated region 1 kb longer than the previously reported one. The 3'-end fragment of the clone hybridized only to the larger species (3.8 kb) of fyn mRNA but not to the smaller one (2.8 kb) on Northern blot analysis. Furthermore, an additional polyadenylation signal sequence was found at the end of this clone. These results indicate that the two mRNA species for fyn are produced by alternative polyadenylation.

Eosinophilic foreign body granuloma after multiple self-administered bee stings

A bee sting can cause a foreign body granuloma of the skin, due to activated macrophages at the stinging site. A 52-year-old woman presented with a large doughnut-shaped ulcerative tumour on the left side of her face. A bean-sized facial papule had grown to a 4.0 x 3.9 x 1.1 cm mass after multiple bee stings induced by herself over a period of 1 year. Histology showed epidermal ulceration with granulomatous inflammatory cell infiltration of many eosinophils. No micro-organisms or foreign bodies were identified. Intralesional triamcinolone acetonide was not effective, but an excellent outcome was obtained using carbon dioxide laser vaporization of the lesion.

Fetal heart rate patterns in postasphyxiated fetal lambs with brain damage

OBJECTIVE

We previously showed that in asphyxiated fetal lambs the duration of hypotension correlated well with the severity of histologic damage to the brain, whereas the duration of bradycardia did not. This study compares fetal heart rate patterns with the degree of histologic damage to the brain.

STUDY DESIGN

Twelve chronically instrumented near-term fetal lambs were subjected to asphyxia by umbilical cord occlusion until fetal arterial pH was <6. 9 and base excess was <-20 mEq/L. An additional 4 fetuses served as sham-asphyxia controls. Fetal heart rate (from electrocardiogram), arterial blood pressure, fetal breathing movements, and electrocorticogram were continuously monitored before, during, and for 72 hours after asphyxia. Fetal brain histologic features were categorized as mild (group 1, n = 5), moderate (group 2, n = 4), and severe (group 3, n = 3). Long-term fetal heart rate variability expressed as amplitude range was assessed visually every 5 minutes from 30 minutes before asphyxia until 2 hours of recovery and at 6, 12, 24, 48, and 72 hours of recovery.

RESULTS

Long-term fetal heart rate variability amplitude decreased from 32 +/- 17 beats/min (mean +/- SEM) preocclusion to 4 +/- 13 beats/min at the end of occlusion (P <.001) without significant differences among the 3 groups. During 10 to 45 minutes of recovery, the long-term variability of group 1 was significantly greater than that of groups 2 and 3. At 24 to 72 hours of recovery, the long-term variability of groups 1 and 2 was significantly higher than that of group 3, which was almost 0. The "checkmark" and sinusoidal fetal heart rate patterns were observed during the recovery period in groups 2 and 3.

CONCLUSIONS

Decreased long-term fetal heart rate variability and the "checkmark" and sinusoidal fetal heart rate patterns were indicators of the severity of asphyxial histologic damage in the fetal brain.