Akt regulates cell survival and apoptosis at a postmitochondrial level

Phosphoinositide 3 kinase/Akt pathway plays an essential role in neuronal survival. However, the cellular mechanisms by which Akt suppresses cell death and protects neurons from apoptosis remain unclear. We previously showed that transient expression of constitutively active Akt inhibits ceramide-induced death of hybrid motor neuron 1 cells. Here we show that stable expression of either constitutively active Akt or Bcl-2 inhibits apoptosis, but only Bcl-2 prevents the release of cytochrome c from mitochondria, suggesting that Akt regulates apoptosis at a postmitochondrial level. Consistent with this, overexpressing active Akt rescues cells from apoptosis without altering expression levels of endogenous Bcl-2, Bcl-x, or Bax. Akt inhibits apoptosis induced by microinjection of cytochrome c and lysates from cells expressing active Akt inhibit cytochrome c induced caspase activation in a cell-free assay while lysates from Bcl-2-expressing cells have no effect. Addition of cytochrome c and dATP to lysates from cells expressing active Akt do not activate caspase-9 or -3 and immunoprecipitated Akt added to control lysates blocks cytochrome c-induced activation of the caspase cascade. Taken together, these data suggest that Akt inhibits activation of caspase-9 and -3 by posttranslational modification of a cytosolic factor downstream of cytochrome c and before activation of caspase-9.

Whole-body optical imaging of green fluorescent protein-expressing tumors and metastases

We have imaged, in real time, fluorescent tumors growing and metastasizing in live mice. The whole-body optical imaging system is external and noninvasive. It affords unprecedented continuous visual monitoring of malignant growth and spread within intact animals. We have established new human and rodent tumors that stably express very high levels of the Aequorea victoria green fluorescent protein (GFP) and transplanted these to appropriate animals. B16F0-GFP mouse melanoma cells were injected into the tail vein or portal vein of 6-week-old C57BL/6 and nude mice. Whole-body optical images showed metastatic lesions in the brain, liver, and bone of B16F0-GFP that were used for real time, quantitative measurement of tumor growth in each of these organs. The AC3488-GFP human colon cancer was surgically implanted orthotopically into nude mice. Whole-body optical images showed, in real time, growth of the primary colon tumor and its metastatic lesions in the liver and skeleton. Imaging was with either a trans-illuminated epifluorescence microscope or a fluorescence light box and thermoelectrically cooled color charge-coupled device camera. The depth to which metastasis and micrometastasis could be imaged depended on their size. A 60-microm diameter tumor was detectable at a depth of 0.5 mm whereas a 1, 800-microm tumor could be visualized at 2.2-mm depth. The simple, noninvasive, and highly selective imaging of growing tumors, made possible by strong GFP fluorescence, enables the detailed imaging of tumor growth and metastasis formation. This should facilitate studies of modulators of cancer growth including inhibition by potential chemotherapeutic agents.

A murine model of peanut anaphylaxis: T- and B-cell responses to a major peanut allergen mimic human responses

BACKGROUND

Peanut allergy affects 0.6% of the US population. At the present time, allergen avoidance is the only therapeutic option. Animal models of food-induced anaphylaxis would facilitate attempts to design novel immunotherapeutic strategies for the treatment of peanut allergy.

OBJECTIVE

The purpose of this study was to develop a murine model of IgE-mediated peanut hypersensitivity that closely mimics human peanut allergy.

METHODS

C3H/HeJ mice sensitized orally with freshly ground whole peanut and cholera toxin as adjuvant were challenged orally 3 and 5 weeks later with crude peanut extract. Anaphylactic reactions were determined. T- and B-cell responses to Ara h 1 and Ara h 2, the major peanut allergens, were characterized by evaluating splenocyte proliferative responses and IgE antibody concentrations. Furthermore, IgE antibodies in the sera of patients with peanut allergy and mice were compared for antibody binding to Ara h 2 isoforms and allergenic epitopes.

RESULTS

Peanut-specific IgE was induced by oral peanut sensitization, and hypersensitivity reactions were provoked by feeding peanut to sensitized mice. The symptoms were similar to those seen in human subjects. Ara h 1- and Ara h 2-specific antibodies were present in the sera of mice with peanut allergy. Furthermore, these Ara h 2-specific IgE antibodies bound the same Ara h 2 isoforms and major allergenic epitopes as antibodies in the sera of human subjects with peanut allergy. Splenocytes from mice with peanut allergy exhibited proliferative responses to Ara h 1 and Ara h 2.

CONCLUSION

This murine model of peanut allergy mimics the clinical and immunologic characteristics of peanut allergy in human subjects and should be a useful tool for developing immunotherapeutic approaches for the treatment of peanut allergy.

Effects of cooking methods on peanut allergenicity

BACKGROUND

Allergy to peanut is a significant health problem. Interestingly, the prevalence of peanut allergy in China is much lower than that in the United States, despite a high rate of peanut consumption in China. In China, peanuts are commonly fried or boiled, whereas in the United States peanuts are typically dry roasted.

OBJECTIVE

The aim of this study was to examine whether the method of preparing peanuts could be a factor in the disparity of allergy prevalence between the 2 countries.

METHODS

Two varieties of peanuts grown in the United States were roasted, boiled, or fried. Proteins were analyzed by using SDS-PAGE and immunoblotting. Allergenicity was compared by using immunolabeling with sera from 8 patients with peanut allergy.

RESULTS

The protein fractions of both varieties of peanuts were altered to a similar degree by frying or boiling. Compared with roasted peanuts, the relative amount of Ara h 1 was reduced in the fried and boiled preparations, resulting in a significant reduction of IgE-binding intensity. In addition, there was significantly less IgE binding to Ara h 2 and Ara h 3 in fried and boiled peanuts compared with that in roasted peanuts, even though the protein amounts were similar in all 3 preparations.

CONCLUSION

The methods of frying or boiling peanuts, as practiced in China, appear to reduce the allergenicity of peanuts compared with the method of dry roasting practiced widely in the United States. Roasting uses higher temperatures that apparently increase the allergenic property of peanut proteins and may help explain the difference in prevalence of peanut allergy observed in the 2 countries.

A murine model of IgE-mediated cow's milk hypersensitivity

BACKGROUND

Cow's milk allergy (CMA) is one of the leading causes of food allergy in children. Understanding the mechanisms involved in the development of CMA has been hampered by the lack of suitable animal models.

OBJECTIVE

We sought to develop a mouse model of IgE-mediated cow's milk hypersensitivity (CMH) that mimics the clinical features of immediate CMA in humans.

METHODS

Three-week-old C3H/HeJ mice were sensitized by intragastric administration of cow's milk (CM) plus cholera toxin and boosted 5 times at weekly intervals.

RESULTS

CM-specific IgE antibody levels were significantly increased at 3 weeks and peaked at 6 weeks after the initial feeding. Intragastric challenge with CM at week 6 elicited systemic anaphylaxis accompanied by vascular leakage, significantly increased plasma histamine, and increased intestinal permeability to casein. Histologic examination of intestinal tissue revealed marked vascular congestion, edema, and sloughing of enterocytes. The role of IgE in mediating CMH was confirmed by abrogation of passive cutaneous anaphylaxis reactions by heat inactivation of immune sera. Development of IgE-mediated CMH in this model is likely to be TH2 cell mediated because in vitro stimulation of spleen cells from mice allergic to CM induced significant increases in the levels of IL-4 and IL-5, but not IFN-gamma.

CONCLUSION

This model should provide a useful tool for evaluating the immunopathogenic mechanisms involved in CMA and for exploring new therapeutic approaches.

Lung cancer and indoor air pollution in Xuan Wei, China

In Xuan Wei County, Yunnan Province, lung cancer mortality is among China's highest and, especially in females, is more closely associated with indoor burning of "smoky" coal, as opposed to wood or "smokeless" coal, than with tobacco smoking. Indoor air samples were collected during the burning of all three fuels. In contrast to wood and smokeless coal emissions, smoky coal emission has high concentrations of submicron particles containing mutagenic organics, especially in aromatic and polar fractions. These studies suggested an etiologic link between domestic smoky coal burning and lung cancer in Xuan Wei.

The IAP family: endogenous caspase inhibitors with multiple biological activities

IAPs (inhibitors of apoptosis) are a family of proteins containing one or more characteristic BIR domains. These proteins have multiple biological activities that include binding and inhibiting caspases, regulating cell cycle progression, and modulating receptor-mediated signal transduction. Our recent studies found the IAP family members XIAP and c-IAP1 are ubiquitinated and degraded in proteasomes in response to apoptotic stimuli in T cells, and their degradation appears to be important for T cells to commit to death. In addition to three BIR domains, each of these IAPs also contains a RING finger domain. We found this region confers ubiquitin protease ligase (E3) activity to IAPs, and is responsible for the auto-ubiquitination and degradation of IAPs after an apoptotic stimulus. Given the fact that IAPs can bind a variety of proteins, such as caspases and TRAFs, it will be of interest to characterize potential substrates of the E3 activity of IAPs and the effects of ubiquitination by IAPs on signal transduction, cell cycle, and apoptosis.

Effect of the Lycium barbarum polysaccharides on age-related oxidative stress in aged mice

Oxidative damage of biomolecules increases with age and is postulated to be a major causal factor of various physiological function disorders. Consequently, the concept of anti-age by antioxidants has been developed. Lycium barbarum fruits have been used as a traditional Chinese herbal medicine and the data obtained in in vitro models have clearly established the antioxidant potency of the polysaccharides isolated from the fruits. In the present study, the age-dependent changes in the antioxidant enzyme activity, immune function and lipid peroxidation product were investigated and effect of Lycium barbarum polysaccharides on age-induced oxidative stress in different organs of aged mice was checked. Lycium barbarum polysaccharides (200, 350 and 500 mg/kg b.w. in physiological saline) were orally administrated to aged mice over a period of 30 days. Aged mice receiving vitamin C served as positive control. Enzymatic and non-enzymatic antioxidants, lipid peroxides in serum and tested organs, and immune function were measured. Result showed that increased endogenous lipid peroxidation, and decreased antioxidant activities, as assessed by superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total antioxidant capacity (TAOC), and immune function were observed in aged mice and restored to normal levels in the polysaccharides-treated groups. Antioxidant activities of Lycium barbarum polysaccharides can be compable with normal antioxidant, vitamin C. Moreover, addition of vitamin C to the polysaccharides further increased the in vivo antioxidant activity of the latter. It is concluded that the Lycium barbarum polysaccharides can be used in compensating the decline in TAOC, immune function and the activities of antioxidant enzymes and thereby reduces the risks of lipid peroxidation accelerated by age-induced free radical.

Quetiapine facilitates oligodendrocyte development and prevents mice from myelin breakdown and behavioral changes

Recent neuroimaging and postmortem studies have reported abnormalities in white matter of schizophrenic brains, suggesting the involvement of oligodendrocytes in the etiopathology of schizophrenia. This view is being supported by gene microarray studies showing the downregulation of genes related to oligodendrocyte function and myelination in schizophrenic brain compared to control subjects. However, there is currently little information available on the response of oligodendrocytes to antipsychotic drugs (APDs), which could be invaluable for corroborating the oligodendrocyte hypothesis. In this study we found: (1) quetiapine (QUE, an atypical APD) treatment in conjunction with addition of growth factors increased the proliferation of neural progenitors isolated from the cerebral cortex of embryonic rats; (2) QUE directed the differentiation of neural progenitors to oligodendrocyte lineage through extracellular signal-related kinases; (3) addition of QUE increased the synthesis of myelin basic protein and facilitated myelination in rat embryonic cortical aggregate cultures; (4) chronic administration of QUE to C57BL/6 mice prevented cortical demyelination and concomitant spatial working memory impairment induced by cuprizone, a neurotoxin. These findings suggest a new neural mechanism of antipsychotic action of QUE, and help to establish a role for oligodendrocytes in the etiopathology and treatment of schizophrenia.

Olanzapine increases in vivo dopamine and norepinephrine release in rat prefrontal cortex, nucleus accumbens and striatum

The in vivo effects of olanzapine on the extracellular monoamine levels in rat prefrontal cortex (Pfc), nucleus accumbens (Acb) and striatum (Cpu) were investigated by means of microdialysis. Sequential doses of olanzapine at 0.5, 3 and 10 mg/kg (s.c.) dose-dependently increased the extracellular dopamine (DA) and norepinephrine (NE) levels in all three brain areas. The increases appeared 30 min after olanzapine administration, reached peaks around 60-90 min and lasted for at least 2 h. The highest DA increases in the Acb and Cpu were induced by olanzapine at 3 mg/kg but at 10 mg/kg in the Pfc. The peak DA increase in the Pfc (421% +/- 46 of the baseline) was significantly larger than those in the Acb (287% +/- 24) and Cpu (278% +/- 28). Similarly, the highest NE increase in the Pfc (414% +/- 40) induced by 10 mg/kg olanzapine was larger than those in the Acb (233% +/- 39) and Cpu (223% +/- 24). The DA and NE increases in the Pfc induced by olanzapine at 3 and 10 mg/kg (s.c.) were slightly larger than those induced by clozapine at the same doses. In contrast, haloperidol (0.5 and 2 mg/kg, s.c.) did not change Pfc DA and NE levels. Extracellular levels of a DA metabolite, DOPAC, and tissue concentrations of a released DA metabolite, 3-methoxytyramine, were also increased by olanzapine, consistent with enhanced DA release. However, olanzapine at the three sequential doses did not alter the extracellular levels of either 5-HT or its metabolite, 5-HIAA, in any of the three brain areas. In conclusion, the present studies demonstrate that in the case of sequential dosing olanzapine more effectively enhances DA and NE release in the Pfc than in the subcortical areas, which may have an impact on its atypical antipsychotic actions.

Food Allergy Herbal Formula-1 (FAHF-1) blocks peanut-induced anaphylaxis in a murine model

BACKGROUND

Peanut allergy is a major cause of fatal and near-fatal anaphylactic reactions to foods. There is no curative therapy for this condition. Traditional Chinese medicines have been reported to have antiallergic properties, which might be useful for treating peanut allergy.

OBJECTIVE

The purpose of this study was to investigate the effects of a Chinese herbal formula, FAHF-1, on peanut anaphylactic reactions in a mouse model of peanut allergy.

METHODS

Mice were sensitized with freshly ground whole peanut in the presence of cholera toxin and boosted 1 and 3 weeks later. FAHF-1 treatment was initiated 1 week later and continued for 7 weeks. After treatment, mice were challenged with peanut, and anaphylactic symptoms, body temperatures, and plasma histamine and IgE levels were measured. T-cell proliferative responses and cytokine production were also determined.

RESULTS

FAHF-1 completely blocked peanut-induced anaphylactic symptoms and markedly reduced mast cell degranulation and histamine release. Peanut-specific serum IgE levels were significantly reduced by 2 weeks of treatment at the time of challenge, and they remained lower 4 weeks after discontinuation of treatment. FAHF-1 significantly reduced peanut-induced lymphocyte proliferation as well as IL-4, IL-5, and IL-13 synthesis but not IFN-gamma synthesis. No toxic effects on liver or kidney functions were observed, nor was there any overall immune suppression.

CONCLUSION

FAHF-1 protected peanut-sensitized mice from anaphylactic reactions and significantly reversed established IgE-mediated peanut allergy. This suggests that FAHF-1 might prove valuable for the treatment of peanut allergy.

Frequent deletions of the human X chromosome distal short arm result from recombination between low copy repetitive elements

Substantial DNA deletions appear to be the molecular basis of several human genetic disorders but rarely account for the majority of observed mutations at any given locus. Exceptions in which deletions do account for the majority of observed abnormalities include the alpha-thalassemias, Duchenne muscular dystrophy, and steroid sulfatase deficiency. Variable deletion breakpoints have been recognized at the alpha-globin and dystrophin loci, but no information is available regarding STS deletions. We have found that these STS alterations usually involve breakpoints within highly similar sequence elements situated approximately 1.9 megabases apart on the X chromosome. It is surprising that these very large deletions produce such mild clinical abnormalities. These results may provide insight into the molecular mechanism of a number of human genetic defects.

Whole-body and intravital optical imaging of angiogenesis in orthotopically implanted tumors

The development of drugs for the control of tumor angiogenesis requires a simple, accurate, and economical assay for tumor-induced vascularization. We have adapted the orthotopic implantation model to angiogenesis measurement by using human tumors labeled with Aequorea victoria green fluorescent protein for grafting into nude mice. The nonluminous induced capillaries are clearly visible against the very bright tumor fluorescence examined either intravitally or by whole-body luminance in real time. The orthotopic implantation model of human cancer has been well characterized, and fluorescence shadowing replaces the laborious histological techniques for determining blood vessel density. Intravital images of orthotopically implanted human pancreatic tumors clearly show angiogenic capillaries at both primary and metastatic sites. A quantitative time course of angiogenesis was determined for an orthotopically growing human prostate tumor periodically imaged intravitally in a single nude mouse over a 19-day period. Whole-body optical imaging of tumor angiogenesis was demonstrated by injecting fluorescent Lewis lung carcinoma cells into the s.c. site of the footpad of nude mice. The footpad is relatively transparent, with comparatively few resident blood vessels, allowing quantitative imaging of tumor angiogenesis in the intact animal. Capillary density increased linearly over a 10-day period as determined by whole-body imaging. Similarly, the green fluorescent protein-expressing human breast tumor MDA-MB-435 was orthotopically transplanted to the mouse fat pad, where whole-body optical imaging showed that blood vessel density increased linearly over a 20-week period. These powerful and clinically relevant angiogenesis mouse models can be used for real-time in vivo evaluation of agents inhibiting or promoting tumor angiogenesis in physiological microenvironments.

Synthetic peptides entrapped in microparticles can elicit cytotoxic T cell activity

Peptides from Plasmodium berghei circumsporozoite protein (CS) and influenza A virus nucleoprotein (NP) were entrapped in microparticles prepared from poly (lactide-co-glycolide) polymers, and the microparticles were administered parenterally to mice. After immunization with single or multiple doses, splenocytes were tested for a cytotoxic T cell (CTL) response and high levels of CTL activity were detected. The CTL induced were CD8+, MHC class I restricted, and could recognize virus infected cells. Peptide entrapped in microparticles of mean size < 500 nm were better inducers of CTL than larger microparticles (mean > 2 microns and above). Microparticles could also be used to deliver lipid modified peptides (lipopeptides) and elicited higher levels of cytolytic activity than either free peptide in microparticles or lipopeptide alone. Microparticles provide a novel way of inducing a CTL response using synthetic peptides.

Sphingomyelin interfacial behavior: the impact of changing acyl chain composition

Sphingomyelins (SMs) containing homogeneous acyl chains with 12, 14, 16, 18, 24, or 26 carbons were synthesized and characterized using an automated Langmuir-type film balance. Surface pressure was monitored as a function of lipid molecular area at constant temperatures between 10 degrees C and 30 degrees C. SM containing lauroyl (12:0) acyl chains displayed only liquid-expanded behavior. Increasing the length of the saturated acyl chain (e.g., 14:0, 16:0, or 18:0) resulted in liquid-expanded to condensed two-dimensional phase transitions at many temperatures in the 10-30 degrees C range. Similar behavior was observed for SMs with lignoceroyl (24:0) or (cerotoyl) 26:0 acyl chains, but isotherms showed only condensed behavior at 10 and 15 degrees C. Insights into the physico-mechanical in-plane interactions occurring within the different SM phases and accompanying changes in SM phase state were provided by analyzing the interfacial area compressibility moduli. At similar surface pressures, SM fluid phases were less compressible than those of phosphatidylcholines with similar chain structures. The area per molecule and compressibility of SM condensed phases depended upon the length of the saturated acyl chain and upon spreading temperature. Spreading of SMs with very long saturated acyl chains at temperatures 30-35 degrees below T(m) resulted in condensed films with lower in-plane compressibilities, but consistently larger cross-sectional molecular areas than the condensed phases achieved by spreading at temperatures only 10-20 degrees below T(m). This behavior is discussed in terms of the enhancement of SM lateral aggregation by temperature reduction, a common approach used during domain isolation from biomembranes.

Murine model of atopic dermatitis associated with food hypersensitivity

BACKGROUND

Atopic dermatitis (AD) is an eczematous skin eruption that generally begins in early infancy and affects up to 12% of the population. The cause of this disorder is not fully understood, although it is frequently the first sign of atopic disease and is characterized by an elevated serum IgE level, eosinophilia, and histologic tissue changes characterized early by spongiosis and a CD4(+) T(H)2 cellular infiltrate. Hypersensitivity to foods has been implicated as one causative factor in up to 40% of children with moderate-to-severe AD.

OBJECTIVE

The purpose of this study was to establish a murine model of food-induced AD.

METHODS

Female C3H/HeJ mice were sensitized orally to cow's milk or peanut with a cholera toxin adjuvant and then subjected to low-grade allergen exposure. Histologic examination of skin lesions, allergen-specific serum Ig levels, and allergen-induced T-cell proliferation and cytokine production were examined.

RESULTS

An eczematous eruption developed in approximately one third of mice after low-grade exposure to milk or peanut proteins. Peripheral blood eosinophilia and elevated serum IgE levels were noted. Histologic examination of the lesional skin revealed spongiosis and a cellular infiltrate consisting of CD4(+) lymphocytes, eosinophils, and mast cells. IL-5 and IL-13 mRNA expression was elevated only in the skin of mice with the eczematous eruption. Treatment of the eruption with topical corticosteroids led to decreased pruritus and resolution of the cutaneous eruption.

CONCLUSION

This eczematous eruption resembles AD in human subjects and should provide a useful model for studying immunopathogenic mechanisms of food hypersensitivity in AD.

Receptor-receptor interactions as an integrative mechanism in nerve cells

Several lines of evidence indicate that interactions among transmission lines can take place at the level of the cell membrane via interactions among macromolecules, integral or associated to the cell membrane, involved in signal recognition and transduction. The present view will focus on this last subject, i.e., on the interactions between receptors for chemical signals at the level of the neuronal membrane (receptor-receptor interaction). By receptor-receptor interaction we mean that a neurotransmitter or modulator, by binding to its receptor, modifies the characteristics of the receptor for another transmitter or modulator. Four types of interactions among transmission lines may be considered, but mainly intramembrane receptor-receptor interactions have been dealt with in this article, exemplified by the heteroregulation of D2 receptors via neuropeptide receptors and A2 receptors. The role of receptor-receptor interactions in the integration of signals is discussed, especially in terms of filtration of incoming signals, of integration of coincident signals, and of neuronal plasticity.

CpG oligodeoxynucleotides can reverse Th2-associated allergic airway responses and alter the B7.1/B7.2 expression in a murine model of asthma

CpG oligodeoxynucleotides (CpG-ODN) administered during Ag sensitization or before Ag challenge can inhibit allergic pulmonary inflammation and airway hyperreactivity in murine models of asthma. In this study, we investigated whether CpG-ODN can reverse an ongoing allergic pulmonary reaction in a mouse model of asthma. AKR mice were sensitized with conalbumin followed by two intratracheal challenges at weekly intervals. CpG-ODN was administered 24 h after the first Ag challenge. CpG-ODN administration reduced Ag-specific IgE levels, bronchoalveolar lavage fluid eosinophils, mucus production, and airway hyperreactivity. We found that postchallenge CpG-ODN treatment significantly increased IFN-gamma concentrations and decreased IL-13, IL-4, and IL-5 concentrations in bronchoalveolar lavage fluids and spleen cell culture supernatants. Postchallenge CpG-ODN treatment also increased B7.1 mRNA expression and decreased B7.2 mRNA expression in lung tissues. These results suggest that CpG-ODN may have potential for treatment of allergic asthma by suppressing Th2 responses during IgE-dependent allergic airway reactions. The down-regulation of Th2 responses by CPG-ODN may be associated with regulation of the costimulatory factors B7.1 and B7.2.

Functional genomics in mice by tagged sequence mutagenesis

Most mammalian genes will soon be characterized as cDNA sequences with little information about their function. To utilize this sequence information for large-scale functional studies, a gene trap retrovirus shuttle vector has been developed to disrupt genes expressed in murine embryonic stem (ES) cells. A library of mutant clones was isolated, and regions of genomic DNA adjacent to 400 independent provirus inserts were cloned and sequenced. The flanking sequences, designated 'promoter-proximal sequence tags', or PSTs, identified 63 specific genes and anonymous cDNAs disrupted as a result of virus integration. The efficiency of tagged sequence mutagenesis suggests that many of the 10,000-20,000 genes expressed in ES cells can be targeted, providing defined mutations for the analysis of gene functions in vivo. In addition, PSTs provide the first expressed sequence tags derived from genomic DNA, and define gene features such as exon boundaries and promoters that are missing from cDNA sequences.

Aromatic L-amino acid decarboxylase: a neglected and misunderstood enzyme

Classically, aromatic L-amino acid decarboxylase (AADC) has been regarded as an unregulated, rather uninteresting enzyme. In this review, we describe advances made during the past 10 years, demonstrating that AADC is regulated both pre- and post-translation. The significance of such regulatory mechanisms is poorly understood at present, but the presence of tissue specific control of expression raises the real possibility of AADC being involved in processes other than neuro-transmitter synthesis. We further discuss clinical and physiological situations in which such regulatory mechanisms may be important, including the intriguing possibility of AADC gene regulation being linked to that of factors thought to have a role in apoptosis and its prevention.

Microvessel density of hepatocellular carcinoma: its relationship with prognosis

PURPOSE

To elucidate the relationship between angiogenesis and prognosis after curative resection of hepatocellular carcinoma (HCC).

METHODS

An immunohistochemical study using anti-CD34 monoclonal antibody was carried out on surgical specimens from 78 HCC patients who had undergone curative resection; microvessel density (MVD) was counted and the overall survival and disease-free survival were analyzed retrospectively.

RESULTS

Blood vessels in the tumor were strongly stained by anti-CD34 antibody, but not those in the surrounding liver parenchyma. There were three types of tumor vessels: capillary-like (n = 59), sinusoid-like (n = 16) and mixed-type (n = 3). The median MVD count was 100 per field. The HCC were designated as hypovascular (n = 36) with an MVD count below 100, and hypervascular (n = 42) with an MVD count of 100 or more per field. The 5-year survival and disease-free survival rates were 49.7% and 42.8% respectively, and statistical analysis showed that the MVD level was not correlated with tumor size, capsule status, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase, and serum HBsAg status. The sinusoid-like tumor vessels appeared more frequently in the more differentiated tumors (P<0.05). No statistical difference in overall and disease-free survival between different MVD levels and microvessel types was found. Tumor size was the only predicting factor in the entire series. In patients with small HCC (< or =5 cm, n = 40), 5-year survival and disease-free survival rates were 58.9% and 52.7% respectively, higher than the values in large HCC (39.8% and 32.0% respectively, P<0.05). The MVD level was an independent predicting factor of disease-free survival, 5-year disease-free survival in the hypovascular group (74.6%) being better than that in the hypervascular group (34.7%, P<0.05).

CONCLUSIONS

The MVD level was not related to tumor size, capsule statuo, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase and serum HBsAg status. In the entire series, tumor size was the only factor influencing survival after curative resection. However, in patients with small HCC, the MVD level was an independent factor of disease-free survival. The pathological and clinical implications of different types of tumor vessels in HCC remain to be studied.

Circ-ITCH regulates triple-negative breast cancer progression through the Wnt/β-catenin pathway

Recent studies indicate that circular RNA (circRNA) is involved in tumorigenesis, but its role in triple-negative breast cancer (TNBC) remains largely unknown. In this study, we characterized the role of circ-ITCH in TNBC and found that circ-ITCH was significantly down-regulated in TNBC tissues and cell lines and closely associated with poor prognosis. We therefore constructed the MDA-MB-231 and BT-549 TNBC cell lines stably expressing circ-ITCH by lentiviral vectors to determine its underlying mechanisms in TNBC progression. Most importantly, over-expression of circ-ITCH remarkably inhibited TNBC proliferation, invasion and metastasis both in vitro and in vivo. Mechanistically, we found that circ-ITCH acts as a sponge for miR-214 and miR-17 to increase expression of its ITCH linear isoform, thereby inactivating Wnt/β-catenin signaling. Our combined results show for the first time that circ-ITCH is a tumor suppressor, a promising prognostic biomarker in TNBC and that its restoration could well be a successful strategy in TNBC.

Intramembrane interactions between neurotensin receptors and dopamine D2 receptors as a major mechanism for the neuroleptic-like action of neurotensin

Evidence has been presented that behavioral actions of NT, inducing its neuroleptic-like action, can be explained on the basis of NT-D2 intramembrane receptor-receptor interactions in the basal ganglia, unrelated to the coexistence phenomenon, leading to reduced affinity and transduction of the D2 agonist binding site. By reducing selectively D2 receptor transduction at the pre- and postsynaptic level, the NT receptor appears capable of switching the DA synapses towards a D1 receptor-mediated transduction, illustrating how receptor-receptor interactions can increase the functional plasticity of central synapses (FIG. 12).

The chinese herbal medicine formula MSSM-002 suppresses allergic airway hyperreactivity and modulates TH1/TH2 responses in a murine model of allergic asthma

BACKGROUND

Asthma is a major public health problem worldwide, and the morbidity and mortality of asthma have increased in the past two decades. The reputed efficacy, low cost, and relative absence of side effects of traditional Chinese medicines (TCMs) have led to increasing interest in the use of TCMs for the treatment of asthma in Western countries. However, there are few well-controlled scientific studies on the efficacy, safety, and mechanisms of action of TCMs used to treat asthma.

OBJECTIVE

The goal of this study was to investigate the effects of the Chinese herbal medicine formula MSSM-002, derived from TCMs used to treat allergic asthma, on a well-characterized mouse model of allergic asthma.

METHODS

Mice sensitized intraperitoneally and challenged intratracheally with conalbumin were treated with MSSM-002 24 hours after the first intratracheal challenge. Dexamethasone-treated, saline solution sham-treated, and naive mice served as controls. The effects of MSSM-002 on allergic airway hyperreactivity, inflammation, antigen-specific antibody production, lung histologic features, and cytokine profiles were evaluated.

RESULTS

MSSM-002 treatment virtually eliminated airway hyperreactivity and markedly reduced the total number of cells and the percent eosinophils in bronchoalveolar lavage fluids compared with the sham-treated group. Lung histologic features showed that MSSM-002 reduced inflammation and mucus production. These effects were equivalent to the effects of dexamethasone, but in contrast to the overall immunosuppressive effects of dexamethasone MSSM-002 treatment decreased antigen-specific IgE, IL-4, IL-5, and IL-13 levels without suppressing IgG2a and IFN-gamma synthesis.

CONCLUSION

MSSM-002 exhibits anti-airway hyperresponsiveness, anti-airway inflammation, and immunoregulatory effects on T(H)1/T(H)2 responses, which may be useful for treatment of allergic asthma.