Self-assessment scale for the community-based and emergency practice

BACKGROUND

For current medical education, community-based primary care for the elderly is an essential topic. This study aimed to establish a scale of community-based assessment for clinical and emergency practice (C-CEP).

METHODS

A self-assessment scale for C-CEP was developed according to four steps. Initially, we reviewed publications from the societies of the United States, British, and Japan regarding educational goals. In addition, we searched MEDLINE for educational goals regarding attitude, skills, and knowledge. Getting together, we established 23 items as the educational goals of the C-CEP. Second, we collected responses for these 23 items from 5th-grade medical students (n = 195). Third, we conducted an exploratory factor analysis (EFA) using their responses to determine the fundamental structure of the self-assessment scale. Finally, a confirmatory factor analysis (CFA) was performed to assess the fitness of the self-assessment scale developing the EFA, resulting in modification of the items.

RESULTS

In EFA and CFA results, C-CEP Scale consisted of four factors with 15 items: "Attitude and communication in emergency care," Basic clinical skills," "Knowledge of community healthcare," and "Knowledge of evidence-based medicine perseverance." The model fit indices were acceptable (Goodness of Fix Index = 0.928, Adjusted Goodness of Fit Index = 0.900, Comparative Fit Index = 0.979, and Root Mean Square Error of Approximation = 0.045). The values of McDonald's omega as an estimate of scale reliability were more than 0.7 in all four factors. As for test-retest reliability, the intraclass correlation coefficients were ≥ 0.58 for all factors. All four factors of the C-CEP Scale correlated positively with the Medical Professionalism Evaluation Scale subscales.

CONCLUSIONS

We developed a valid and reliable self-assessment scale to assess student competence.

CCL8 deficiency in the host abrogates early mortality of acute graft-versus-host disease in mice with dysregulated IL-6 expression

Although allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for diverse malignant and nonmalignant diseases, acute graft-versus-host disease (aGVHD) is strongly linked to mortality caused by HSCT. We previously reported that CC chemokine ligand 8 (CCL8) is closely correlated to aGVHD mortality in both humans and mice. To study the role of CCL8 in aGVHD, CCL8 knockout (CCL8-/-) mice were transplanted with fully allogeneic marrow grafts. These mice exhibited a significant reduction in mortality (90.0% vs. 23.4% survival for CCL8-/- vs. wild-type recipients at day 28, p < 0.0001). As a result, apparent prolonged median survival from 9 days in wild-type mice to 45 days in CCL8-/- mice was observed. Acute GVHD pathology and liver dysfunction in CCL8-/- mice were significantly attenuated compared with those in wild-type mice. In association with the reduced mortality, a surge of plasma interleukin (IL)-6 was observed in CCL8-/- recipients with allogeneic marrow, which was significantly increased compared with wild-type mice that received allografts. Donor T-cell expansion and plasma levels of interferon-γ and TNF-α during aGVHD were similar in both types of mice. Collectively, these findings indicate that CCL8 plays a major role in aGVHD pathogenesis with possible involvement of an IL-6 signaling cascade.

Elucidation of Melanogenesis Cascade for Identifying Pathophysiology and Therapeutic Approach of Pigmentary Disorders and Melanoma

Melanogenesis is the biological and biochemical process of melanin and melanosome biosynthesis. Melanin is formed by enzymic reactions of tyrosinase family proteins that convert tyrosine to form brown-black eumelanin and yellow-red pheomelanin within melanosomal compartments in melanocytes, following the cascades of events interacting with a series of autocrine and paracrine signals. Fully melanized melanosomes are delivered to keratinocytes of the skin and hair. The symbiotic relation of a melanocyte and an associated pool of keratinocytes is called epidermal melanin unit (EMU). Microphthalmia-associated transcription factor (MITF) plays a vital role in melanocyte development and differentiation. MITF regulates expression of numerous pigmentation genes for promoting melanocyte differentiation, as well as fundamental genes for maintaining cell homeostasis. Diseases involving alterations of EMU show various forms of pigmentation phenotypes. This review introduces four major topics of melanogenesis cascade that include (1) melanocyte development and differentiation, (2) melanogenesis and intracellular trafficking for melanosome biosynthesis, (3) melanin pigmentation and pigment-type switching, and (4) development of a novel therapeutic approach for malignant melanoma by elucidation of melanogenesis cascade.

Longitudinal observation of ten family members with idiopathic basal ganglia calcification: A case report

BACKGROUND

Familial idiopathic basal ganglia calcification (FIBGC) is a rare autosomal dominant disorder that causes bilateral calcification of the basal ganglia and/or cerebellar dentate nucleus, among other locations.

CASE SUMMARY

The aim of this study is to report 10 cases of FIBGC observed in a single family. Seven patients showed calcification on their computed tomography scan, and all of these patients carried the SLC20A2 mutation. However, individuals without the mutation did not show calcification. Three patients among the 7 with calcification were symptomatic, while the remaining 4 patients were asymptomatic. Additionally, we longitudinally observed 10 subjects for ten years. In this paper, we mainly focus on the clinical course and neuroradiological findings in the proband and her son.

CONCLUSION

The accumulation of more case reports and further studies related to the manifestation of FIBGC are needed.

Development of the Undergraduate Version of the Interprofessional Learning Scale

PURPOSE

The undergraduate version of the Interprofessional Learning Scale (UIPLS) was developed to evaluate students' competency in interprofessional education because the existing scales were too professional for entry-level students to understand and respond to effectively. In addition, existing scales have some noted problems with validity and reliability.

METHODS

An early 49-item version of the UIPLS was completed by 837 first-year students from two universities and one technical college, including departments for various professionals, in Hokkaido prefecture, Japan. The most common age group was 18-19 years (89.4%) and 61.2% were women. Ten items from the Minnesota Multiphasic Personality Inventory were used to exclude respondents who tended to create a socially favorable impression and/or a possible random and incorrectly scored profile. Kikuchi's Social Skills Scale (18 items) was also used as an external standard to demonstrate the convergent validity of the UIPLS.

RESULTS

Eighteen items across four factors were extracted by factor analysis: "reflection on group work," "attitude towards group work," "knowledge of interprofessional working," and "skill in group work." Internal consistency was confirmed by Cronbach's alpha coefficient (>0.75).

CONCLUSIONS

With good indicators of its validity and reliability, the UIPLS shows some promising aspects to evaluate students' competency for interprofessional working.

Proteomics analysis of site- and stage-specific protein expression after peripheral nerve injury

BACKGROUND

The peripheral nervous system has greater regenerative potential than the CNS. This fact suggests the existence of molecules that act as key factors in nerve regeneration during molecular changes in the peripheral nervous system.

METHODS

The right sciatic nerve of female Sprague-Dawley rats was exposed and transected at the mid-thigh level. Animals were sacrificed at 5, 10 or 35 days after nerve transection. Proximal and distal nerve segments (1-cm in length) were dissected. We then sought to observe overall molecular changes after peripheral nerve injury using a proteomic approach. For an overview of the identified proteins, each protein was classified according to its biological and molecular functions. We identified a number of proteins showing site- and stage-specific patterns of expression.

RESULTS

Both proximal and distal molecular changes at 5, 10 and 35 days after nerve transection were investigated, and a total of 2353 proteins were identified. Among the various expression patterns observed, aFGF and GAP-43 were found to increase in the proximal stump at 10 days after transection, and PN-1, RPL9 and prosaposin increased in the distal stump at 5 days after transection. Among these proteins, aFGF, GAP-43, PN-1 and prosaposin were found to be associated with nerve regeneration.

CONCLUSION

We demonstrated that aFGF, GAP-43, PN-1 and prosaposin expression increased at specific stages and in specific sites, such as the proximal or distal stump, after nerve transection by comprehensive measurement using proteomics analysis. We believe that these specific expression patterns might play important roles during regeneration after nerve injury.

The Serum Level of KL-6 Is Associated with the Risk of Insulin Resistance and New-onset Diabetes Mellitus: The Tanno-Sobetsu Study

Objective Inflammatory cytokines generated in visceral fat have been shown to contribute to the development of insulin resistance. The involvement of pulmonary inflammation in insulin resistance remains unclear, but smoking is known to be a risk factor for diabetes as well as chronic obstructive pulmonary disease. We herein examined the hypothesis that increased serum levels of lung interstitial injury biomarkers [surfactant protein (SP)-A, SP-D and Krebs von den Lungen (KL)-6] are associated with the risk of diabetes development. Methods For cross-sectional and longitudinal analyses, we enrolled 750 apparently healthy non-diabetic subjects who received annual examinations in 2011 or 2012 in the Tanno-Sobetsu cohort. Results A cross-sectional analysis showed that distinct clinical parameters were associated with SP-A, SP-D and KL-6. In a multiple regression analysis, independent explanatory variables were Brinkman index and brain natriuretic peptide (BNP) for SP-A, sex (women), BNP and body mass index (BMI) for SP-D, and age and BMI for KL-6. A longitudinal analysis of 415 subjects who received annual examinations in both 2011 and 2014 showed that 13 (3.1%) of the patients developed type 2 diabetes during the 3-year follow-up. A multiple logistic regression analysis showed the KL-6 levels, systolic blood pressure and homeostasis model assessment of insulin resistance (HOMA-IR) in 2011 to be independently associated with new-onset diabetes. In a multiple regression analysis for HOMA-IR in 2014, the KL-6 level and BMI in 2011 were selected as explanatory variables. Conclusion A modest elevation of the serum KL-6 level is therefore considered to be associated with the risk for insulin resistance development and new-onset diabetes mellitus in a general population.

Consensus paper of the WFSBP task force on biological markers: biological markers for alcoholism

OBJECTIVES

This article presents an overview of the current literature on biological markers for alcoholism, including markers associated with the pharmacological effects of alcohol and markers related to the clinical course and treatment of alcohol-related problems. Many of these studies are well known, while other studies cited are new and still being evaluated.

METHODS

In this paper we first describe known biomarkers of alcohol-related disorders, review their features and the problems involved in their use. We then consider future developments on biomarkers and their possible impact on the field.

RESULTS

More recent findings cited include the work on type 7 adenylcyclase (AC) polymorphism and its lower expression levels in female alcoholics. Neuroimaging studies involving biomarkers have also reported brain volume reductions of gray and white matter, including amygdala and subcortical regions in alcoholic patients, while a high association between the copy number variations (CNVs) in 6q14.1/5q13.2 and alcohol dependence has more recently been identified in genetic studies.

CONCLUSIONS

In addition to their possible importance for diagnosis, biomarkers may have utility for predicting prognosis, progression of the disorder, the development of new treatments, and monitoring treatment effects. Although such findings should be verified in independent studies, the search for new biomarkers is continuing. Several potential candidate biomarkers have been found recently in blood, imaging, and genetic studies with encouraging results.

Effects of atelocollagen on neural stem cell function and its migrating capacity into brain in psychiatric disease model

Stem cell therapy is well proposed as a potential method for the improvement of neurodegenerative damage in the brain. Among several different procedures to reach the cells into the injured lesion, the intravenous (IV) injection has benefit as a minimally invasive approach. However, for the brain disease, prompt development of the effective treatment way of cellular biodistribution of stem cells into the brain after IV injection is needed. Atelocollagen has been used as an adjunctive material in a gene, drug and cell delivery system because of its extremely low antigenicity and bioabsorbability to protect these transplants from intrabody environment. However, there is little work about the direct effect of atelocollagen on stem cells, we examined the functional change of survival, proliferation, migration and differentiation of cultured neural stem cells (NSCs) induced by atelocollagen in vitro. By 72-h treatment 0.01-0.05% atelocollagen showed no significant effects on survival, proliferation and migration of NSCs, while 0.03-0.05% atelocollagen induced significant reduction of neuronal differentiation and increase of astrocytic differentiation. Furthermore, IV treated NSCs complexed with atelocollagen (0.02%) could effectively migrate into the brain rather than NSC treated alone using chronic alcohol binge model rat. These experiments suggested that high dose of atelocollagen exerts direct influence on NSC function but under 0.03% of atelocollagen induces beneficial effect on regenerative approach of IV administration of NSCs for CNS disease.

Evaluation of annexin A5 as a biomarker for Alzheimer's disease and dementia with lewy bodies

Background: Alzheimer's disease (AD) differs from other forms of dementia in its relation to amyloid beta peptide (Aβ₄₂). Using a cell culture model we previously identified annexin A5, a Ca²⁺, and phospholipid binding protein, as an AD biomarker. Plasma level of annexin A5 was significantly higher in AD patients compared to that in a control group. On the other hand, AD has been identified to share a number of clinical and pathological features with Dementia with Lewy bodies (DLB). The present study was done to examine whether or not plasma annexin A5 is a specific marker for AD, when being compared with the levels of DLB patients. As Apolipoprotein E (ApoE) gene subtype ε4 (ApoE-ε4) has been noticed as the probable genetic factor for AD, we also examined and compared ApoE genotype in both AD and DLB.

Methods: Blood samples were obtained from 150 patients with AD (aged 77.6 ± 6.5 years), 50 patients of DLB (79.4 ± 5.0) and 279 community-dwelling healthy elderly individuals of comparable age and sex (75.6 ± 8.1). All AD patients met NINCDS-ADRDA criteria and all DLB patients were diagnosed as probable DLB according to the latest consensus diagnostic criteria. Quantification was done using the Chemiluminescent Enzyme Immunoassay (CLEIA) Technique (SphereLight assay) using the monoclonal antibodies against annexin A5. DNA genotyping of ApoE was performed by distinguishing unique combinations of Hha1 fragments of PCR-amplified genomic DNA products.

Results: The plasma level of annexin A5 was significantly higher in AD patients than in the healthy individuals (control) (P < 0.0001). The plasma annexin A5 level was also significantly higher in DLB patients than in the control group (P < 0.0001). From the ROC curves with plasma annexin A5 concentrations, the mean areas under the curve were 0.863 and 0.838 for the AD/control and DLB/control, respectively. The rate of ApoE4 carrier status and the frequency of the ε4 allele were significantly higher in AD or DLB than in control and there was no significant difference between AD and DLB.

Conclusions: These results suggest that both annexin A5 and ApoE4 are common markers for AD and DLB.

Pulmonary surfactant protein A protects lung epithelium from cytotoxicity of human β-defensin 3

Defensins are important molecules in the innate immune system that eliminate infectious microbes. They also exhibit cytotoxicity against host cells in higher concentrations. The mechanisms by which hosts protect their own cells from cytotoxicity of defensins have been poorly understood. We found that the cytotoxicity of human β-defensin 3 (hBD3) against lung epithelial cells was dose-dependently attenuated by pulmonary surfactant protein A (SP-A), a collectin implicated in host defense and regulation of inflammatory responses in the lung. The direct interaction between SP-A and hBD3 may be an important factor in decreasing this cytotoxicity because preincubation of epithelial cells with SP-A did not affect the cytotoxicity. Consistent with in vitro analysis, intratracheal administration of hBD3 to SP-A(-/-) mice resulted in more severe tissue damage compared with that in WT mice. These data indicate that SP-A protects lung epithelium from tissue injury caused by hBD3. Furthermore, we found that the functional region of SP-A lies within Tyr(161)-Lys(201). Synthetic peptide corresponding to this region, tentatively called SP-A Y161-G200, also inhibited cytotoxicity of hBD3 in a dose-dependent manner. The SP-A Y161-G200 is a candidate as a therapeutic reagent that prevents tissue injury during inflammation.

Investigation of annexin A5 as a biomarker for Alzheimer's disease using neuronal cell culture and mouse model

Alzheimer's disease (AD) differs from other forms of dementia in its relation to amyloid beta peptide (Abeta). Abeta, a proteolytic product of amyloid precursor proteins (APP), has a toxic effect on neuronal cells, which involves perturbation of their Ca(2+) homeostasis. This effect implies that changes of protein expression in neuronal cells with calcium stress should provide a molecular marker for this disease. In the present study, we used the supernatant from a neuronal cell culture after incubation with or without Abeta and isolated a Ca(2+)-dependent acidic phospholipid binding fraction to perform a proteomic study. Several unique proteins were identified after incubation with Abeta. We focused on annexin A5, among these proteins, because it binds both Ca(2+) and lipids likely to be involved in calcium homeostasis. Tg2576 transgenic mice (AD model) overexpressing mutant human APP showed a significant increase of annexin A5 in the brain cortex but not in other organs, including liver, kidney, lung, and intestine. In human plasma samples, the level of annexin A5 was significantly increased in a proportion of AD patients compared with a control group (P < 0.0001 in the logistic regression analysis). From the receiver operating characteristic (ROC) curve with plasma annexin A5 concentrations, the mean area under the curve (AUC 0.898) suggests that annexin A5 is a favorable marker for AD.

Rab7 is a critical mediator in vesicular transport of tyrosinase-related protein 1 in melanocytes

How melanosomal proteins such as enzymic proteins (tyrosinase and tyrosinase-related proteins, Tyrps) and structural protein (gp100) are transported from Golgi to melanosomal compartments is not yet fully understood. A number of small GTPases have been found to be associated with melanosomes and we have identified one of them, Rab7, a regulator of vesicular transport, organelle motility, phospholipid signaling and cytosolic degradative machinery, as being involved in the transport of Tyrp1 from Golgi to stage I melanosomes. This study further characterizes the role of Rab7 as a regulator of differential sorting of melanosomal proteins in this process. Murine melanocytes were transiently transfected with a plasmid encoding either wild-type (Rab7WT), constitutively active (Rab7Q67L) or dominant-negative (Rab7N125I and Rab7T22N) Rab7. Through immunocytostaining and confocal laser scanning microscopy, we quantitatively compared the bio-distribution of melanosomal proteins between Rab7WT-expressing cells and mutant Rab7-expressing cells. We also characterized their differential elimination from melanosomal compartments by Rab7 by utilizing a proteasome inhibitor, MG132. Our findings indicate that Rab7 plays an important role in differential sorting of tyrosinase, Tyrp1 and gp100 in early melanogenesis cascade, and that it is more specifically involved with Tyrp1 than tyrosinase and gp100 in the trafficking from Golgi to melanosomes and the specific exit from the degradative process.

Upregulation of plasma CCL8 in mouse model of graft-vs-host disease

OBJECTIVE

Using a proteomic approach, we recently identified plasma CCL8 as a potential biomarker for diagnosis of graft-vs-host-disease (GVHD) in mice as well as humans. Because mass spectrometric analysis is only semi-quantitative, a quantitative method of measuring plasma CCL8 levels in mice is needed.

MATERIALS AND METHODS

We established an enzyme-linked immunosorbent assay for the quantitative measurement of CCL8 concentrations in mouse plasma.

RESULTS

Our newly established enzyme-linked immunosorbent assay revealed that the plasma CCL8 concentrations (mean +/- standard error; n=12) were 1287+/-55.7 ng/mL and 1604+/-110.8 ng/mL on days 7 and 14 after allogeneic bone marrow transplantation (BMT), respectively, while the plasma concentrations was 316.6+/-16.3 ng/mL on day 7 after syngeneic BMT. A Western blotting analysis also showed a difference in the plasma CCL8 levels between the allogeneic and syngeneic BMT groups, as did clinical GVHD scores. Neither lipopolysaccharide nor poly(I:C) elevated the plasma CCL8 concentrations, although a dramatic increase in interleukin-6 was detected after both treatments.

CONCLUSION

An elevated plasma CCL8 concentration may be a promising plasma marker for GVHD in mouse models.

Lithium-induced suppression of transcription repressor NRSF/REST: effects on the dysfunction of neuronal differentiation by ethanol

Lithium, a mood-stabilizing drug, is widely used to treat bipolar affective disorder. Recent studies have demonstrated that lithium has neuroprotective and neurotrophic properties, which may relate to its clinical effectiveness. Ethanol is a deleterious agent that causes various kinds of neuronal damage to both the developing and adult brain. In this study, we investigated the potential of lithium to produce recovery of ethanol-induced suppressed neuronal differentiation at ethanol concentrations lower than those that affect the viability of neural stem cells (NSCs). We evaluated the effect of lithium on neuronal differentiation of NSCs obtained from rat embryos. To elucidate the molecular mechanisms underlying the altered neuronal differentiation induced by lithium and ethanol, we focused on neuron-restrictive silencer factor (NRSF), which represses transcription of neuronal genes in the terminal stage of NSC differentiation. Lithium increased neuronal differentiation and decreased ethanol-induced suppression of neuronal differentiation of NSCs. Furthermore, lithium reduced the DNA binding activity and protein level of NRSF enhanced by ethanol. Based on our findings, we speculate that lithium may be efficacious in the treatment of ethanol-induced neurological deficits.

[Plasma analysis of rheumatoid arthritis by SELDI]

To identify protein biomarkers linking to disease activity and treatment responses of patients with rheumatoid arthritis (RA), proteomic study using mass spectrometric analysis of plasma proteins was performed. Proteomic profiling technologies can simultaneously resolve and analyze multiple proteins in plasma. Evaluation of multiple proteins of the plasma will be essential to discover protein biomarkers. In this study, we used protein chip surface enhanced laser desorption/ionization time of flight mass spectrometry approach (SELDI-TOF MS). Through differential profiling of plasma proteins, we selected two prospective candidate biomarkers. One mass spectrometric peak distinguished patients with RA from healthy controls was transthyretin (TTR) and the other distinguished inactive patients with RA from patients with active RA was Serum Amyloid A (SAA). This study demonstrates that proteomic profiling using mass spectrometry of plasma greatly facilitates global discovery and verify clinically relevant sets of disease biomarker directly links to disease activity and treatment responses.

Allosterism in Membrane Binding: A Common Motif of the Annexins?

Annexins are a family of proteins generally described as Ca(2+)-dependent for phospholipid binding. Yet, annexins have a wide variety of binding behaviors and conformational states, some of which are lipid-dependent and Ca(2+)-independent. We present a model that captures the cation and phospholipid binding behavior of the highly conserved core of the annexins. Experimental data for annexins A4 and A5, which have short N-termini, were globally modeled to gain an understanding of how the lipid-binding affinity of the conserved protein core is modulated. Analysis of the binding behavior was achieved through use of the lanthanide Tb(3+) as a Ca(2+) analogue. Binding isotherms were determined experimentally from the quenching of the intrinsic fluorescence of annexins A4 and A5 by Tb(3+) in the presence or absence of membranes. In the presence of lipid, the affinity of annexin for cation increases, and the binding isotherms change from hyperbolic to weakly sigmoidal. This behavior was modeled by isotherms derived from microscopic binding partition functions. The change from hyperbolic to sigmoidal binding occurs because of an allosteric transition from the annexin solution state to its membrane-associated state. Protein binding to lipid bilayers renders cation binding by annexins cooperative. The two annexin states denote two affinities of the protein for cation, one in the absence and another in the presence of membrane. In the framework of this model, we discuss membrane binding as well as the influence of the N-terminus in modifying the annexin cation-binding affinity by changing the probability of the protein to undergo the postulated two-state transition.

Attenuation of brain derived neurotrophic factor (BDNF) by ethanol and cytoprotective effect of exogenous BDNF against ethanol damage in neuronal cells

Ethanol-induced cell damage was investigated using human neuroblastomas SH-SY5Y cells, which can be differentiated by retinoic acid. With 100 mM or more of ethanol, cytotoxicity was significantly higher in undifferentiated cells than in differentiated cells. Thus, a severer effect of ethanol was observed in undifferentiated cells. In differentiated cells it was shown that the secreted amount of brain derived neurotrophic factor (BDNF) and the cyclic AMP responsive element binding protein (CREB) activity were significantly reduced by ethanol. These effects may be involved in ethanol-induced cell damage in differentiated cells. It was reported that neurotrophic factors have protective effects and that the hippocampus exclusively was damaged by ethanol. Since SH-SY5Y cell is a cell line (a neuronal cell model) and similar cytotoxic effect of ethanol was observed in both SH-SY5Y and primary culture neuronal cells, it will be favorable to use primary culture cells to test a protective effect of BDNF. Exogenous BDNF was shown to have a protective effect against ethanol-induced damage in primary culture neurons from rat hippocampi.

Calcium-dependent regulation of tumour necrosis factor-alpha receptor signalling by copine

The role of copines in regulating signalling from the TNF-alpha (tumour necrosis factor-alpha) receptor was probed by the expression of a copine dominant-negative construct in HEK293 (human embryonic kidney 293) cells. The construct was found to reduce activation of the transcription factor NF-kappaB (nuclear factor-kappaB) by TNF-alpha. The introduction of calcium into HEK293 cells either through the activation of muscarinic cholinergic receptors or through the application of the ionophore A23187 was found to enhance TNF-alpha-dependent activation of NF-kappaB. This effect of calcium was completely blocked by the copine dominant-negative construct. TNF-alpha was found to greatly enhance the expression of endogenous copine I, and the responsiveness of the TNF-alpha signalling pathway to muscarinic stimulation increased in parallel with the increased copine I expression. The copine dominant-negative construct also inhibited the TNF-alpha-dependent degradation of IkappaB, a regulator of NF-kappaB. All of the effects of the dominant-negative construct could be reversed by overexpression of full-length copine I, suggesting that the construct acts specifically through competitive inhibition of copine. One of the identified targets of copine I is the NEDD8-conjugating enzyme UBC12 (ubiquitin C12), that promotes the degradation of IkappaB through the ubiquitin ligase enzyme complex SCF(betaTrCP). Therefore the copine dominant-negative construct might inhibit TNF-alpha signalling by dysregulation or mislocalization of UBC12. Based on these results, a hypothesis is presented for possible roles of copines in regulating other signalling pathways in animals, plants and protozoa.

Augmentation of ethanol-induced cell damage and activation of nuclear factor-kappa B by annexin IV in cultured cells

BACKGROUND

We previously reported that the amount of annexin IV expression was increased in culture cells by exposure to ethanol. Here, to investigate the physiologic role of annexin IV, we analyzed ethanol-induced cytotoxicity and nuclear factor (NF)-kappa B activity by using annexin IV-overexpressed cells.

METHODS

Annexin IV overexpression was performed by transfection of expression vector, in which annexin IV complementary DNA was ligated, to culture cells (rat glioma C6 cells and human neuroblastoma SH-SY5Y cells). Ethanol-induced cytotoxicity was assayed by measuring the mitochondrial enzyme (dehydrogenase) activity or trypan blue exclusion. NF-kappa B activity was measured by electrophoretic mobility shift assay with a kappa B-oligonucleotide probe.

RESULTS

Ethanol-induced cytotoxicity was increased by overexpression of annexin IV in both C6 cells and SH-SY5Y cells. Annexin IV overexpression augmented ethanol-induced NF-kappa B activation.

CONCLUSIONS

Ethanol-induced increase in annexin IV expression might amplify ethanol-induced cytotoxicity via NF-kappa B activation.

Ethanol-induced augmentation of annexin IV in cultured cells and the enhancement of cytotoxicity by overexpression of annexin IV by ethanol

The annexins are a family of highly homologous Ca(2+) and phospholipid binding proteins. The expressive amounts of several annexins have been shown to alter in certain pathological states such as brain ischemia and Alzheimer's disease. It has been demonstrated that ethanol induces cytotoxicity, which results in brain damage. In this study, we examined the relationship between ethanol-induced cytotoxicity and the intrinsic amount of annexins using cell lines (rat glioma C6 cells and human adenocarcinoma A549 cells). A decrease in the mitochondrial enzyme (dehydrogenase) activity, which is widely used to measure cytotoxicity, was observed with a high concentration of ethanol (200 mM or more) after a 24-h exposure in both C6 and A549 cells. Western blot analysis revealed that the amount of annexin IV was augmented in both cells by ethanol, whereas levels of annexins I and V were unchanged. The amount of annexin IV was augmented with increasing concentration of ethanol. The overexpression of annexin IV in C6 cells by transfection with annexin IV-DNA enhanced ethanol-induced cell lesion and was accompanied by NFkappaB activation. Thus, it might be indicated that the amount of annexin IV is selectively augmented and this augmentation facilitates the development of cell lesion by ethanol.

Ethanol-induced augmentation of annexin IV expression in rat C6 glioma and human A549 adenocarcinoma cells

BACKGROUND

We previously reported that the amount of annexin IV significantly increased in the postmortem brains of alcoholics compared with controls. To investigate further whether ethanol directly affects cellular expression of annexins in a cell, we used cell lines and compared the amounts of annexins between ethanol-exposed and control cells.

METHODS

Two kinds of cells (rat glioma C6 cells and human adenocarcinoma A549 cells) were used in the present study. Western blot analysis was performed to quantify expressed amounts of annexins using anti-annexin I, IV, and V antibodies. The mitochondrial enzyme (dehydrogenase) and caspase 3 activities were measured to assess cell damage (apoptosis) by ethanol.

RESULTS

Expressive augmentation of annexin IV was shown in both C6 and A549 cells after a 5-hr exposure to 200 mM of ethanol, whereas amounts of annexins I and V were not changed. Both the mitochondrial dehydrogenase and caspase 3 activities were altered under the same conditions in C6 cells, indicating the induction of cell damage (apoptosis), whereas both of these enzyme activities were unchanged in A549 cells under the same conditions.

CONCLUSIONS

The amount of annexin IV seemed to increase before the induction of cell damage by ethanol. Annexin IV might be one of the specific markers for the effect of ethanol.

Binding of annexins to lung lamellar bodies and the PMA-stimulated secretion of annexin V from alveolar type II cells

To identify lung lamellar body (LB)-binding proteins, the fractions binding to LB-Sepharose 4B in a Ca(2+)-dependent manner from the lung soluble fractions were analyzed with Mono Q column. Four annexins (annexins III, IV, V, and VIII) were identified by partial amino acid sequence analyses as the LB-binding proteins in the lung soluble fractions. A control experiment using phospholipid (phosphatidylserine/phosphatidylglycerol/phosphtidylcholine) liposome-Sepharose 4B revealed that annexins III, IV and V were the Ca(2+)-dependent proteins binding to the column in the lung soluble fractions, while annexin VIII was not detected. Thus, annexin VIII might preferentially bind to LB. On the other hand, the only Ca(2+)-dependent LB-binding protein identified in the bronchoalveolar lavage fluids was annexin V. It was further demonstrated that annexin V was secreted by isolated alveolar type II cells from rats and that the secretion was stimulated by the addition of phorbol ester (PMA), a potent stimulator of surfactant secretion. The PMA-dependent stimulation of annexin V was attenuated by preincubation with surfactant protein-A (SP-A), a potent inhibitor of surfactant secretion. As LB is thought to be an intracellular store of pulmonary surfactant, which is secreted by alveolar type II cells, annexin V is likely to be secreted together with the lamellar body.

Alteration of annexin IV expression in alcoholics

Western blot analysis was performed by using a specific antibody to measure annexin IV in human postmortem brain samples from alcoholic subjects. The analysis showed a significantly augmented expression in the hippocampus compared with controls, whereas the expression in the frontal cortex was equivalent in both groups. Annexin IV expression in the occipital cortex tended to increase in alcoholics. It was shown further that autoantibodies to annexin IV were increased significantly in alcoholic patients compared with controls. Thus, annexin IV may become a novel biological marker for alcoholics.

cAmp signaling cascade: a promising role in ethanol tolerance and dependence

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Subhash C. Pandey and Toshikazu Saito. The presentations were (1) Action of ethanol on cAMP signaling pathways, by M. Yoshimura; (2) Alterations in the G protein adenylyl cyclase system and their mRNA levels in alcoholics, by H. Sohma; (3) The role of the CREB gene transcription factor in ethanol dependence and preference, by Subhash C. Pandey; and (4) The efficacy of adenylyl cyclase signal transduction to the nucleus in primary alcoholics, by M. E. Götz.

Elevation of carboxyl methylation activity on GTP-binding protein gamma-subunit in synovial tissues from rheumatoid arthritis: how does elevation of the methylation relate to the signal transduction system of rheumatoid arthritis?

We examined guanosine triphosphate (GTP)-binding proteins (G-proteins) in synovial tissues obtained from patients with rheumatoid arthritis or osteoarthritis. The results of immunoblot analysis with anti-bovine G-protein betagamma-subunit antibody in the rheumatoid synovial tissue were similar to those in the osteoarthritis synovial tissue. On the other hand, the carboxyl methylation activity on G-protein gamma-subunit in the rheumatoid synovial tissue was enhanced compared with that in the osteoarthritis synovial tissues: Km and Vm values were 2.6 microM and 10 pmol/mg x min, respectively, for the rheumatoid arthritis, and 4.8 microM and 5.6 pmol/mg x min, respectively, for the osteoarthritis. These results suggest that G-protein-linked signal transduction, in reference to carboxyl methylation of the gamma-subunit, is affected in rheumatoid tissues.

Differential lipid specificities of the repeated domains of annexin IV

The roles of the four domains of annexin IV in binding to phospholipids and glycolipids were assessed by analyzing the binding of a group of mutant annexins IV in which one or more of the four domains was inactivated by replacing a critical amino residue(s) (Asp or Glu) with the neutral residue Ala. The data reveal that individual annexin domains may have characteristic affinities for different lipids. In particular, inactivation of the fourth domain inhibits the binding to phosphatidylserine (PS) and phosphatidylinositol (PI) but not to phosphatidylglycerol (PG), suggesting that this domain specifically can accommodate the larger head groups of PS and PI whereas the other three domains may form more restricted binding pockets. In order to block binding to PG, domain 1, or both domains 2 and 3 must be inactivated in addition to domain 4, suggesting that all four domains may be able to accommodate the headgroup of PG to some extent. Binding to acidic glycolipids (sulfatides) was also sensitive to inactivation of domain 4. However, in the case of sulfatides the nature of the binding reaction is fundamentally different compared with the binding to phospholipids since the interaction with sulfatides was highly sensitive to an increase in ionic strength. The binding to sulfatides may depend therefore on charge-charge interactions whereas the binding to phospholipid may involve a more specific interaction between the lipid headgroup and the protein surface, and/or interaction of the protein with the hydrophobic portion of a lipid bilayer.

Improvement of ischaemia-reperfusion injury by lazaroid U74389G in rat lung transplantation model

The effect of lazaroid 74389G on ischaemia-perfusion injury in a rat lung transplantation model was investigated using three administration methods. In all groups, the University of Wisconsin (UW) solution was used as a flush and preservation solution at 4 degrees C, and lungs were stored for 12 h. Group I rats (controls) were not given any lazaroid treatment. In group II, lazaroid U74389G was added to the UW solution (100 micromol/l). In group III, lazaroid (10 mg/kg) was intravenously injected in the donors 30 min before lung ischaemia. Group IV received lazaroid treatment by the combined methods of groups II and III. In all the experimental groups (II-IV), recipient rats were given lazaroid (6 mg/kg) intravenously 30 min before reperfusion. Lazaroid improved the gas exchange function (groups II, III and IV), reduced the tissue lipid peroxides (group II) and ameliorated histologic lung damage (group II). The results thus seemed to be better in group II than in groups III and IV.

Characteristics of the inhibitory effect of calmodulin on specific [125i]omega-conotoxin GVIA binding to crude membranes from chick brain

The characteristics of the inhibitory effect of calcium ion (Ca2+)/calmodulin (CaM) on specific [125I]-omega-conotoxin GVIA (125I-omega-CTX) binding and on the labeling of 125I-omega-CTX to crude membranes from chick brain were investigated. The inhibitory effect of Ca2+/CaM depended on the concentrations of free Ca2+ and CaM. The IC50 values for free Ca2+ and CaM were about 2.0 x 10(-8) M and 3.0 microg protein/ml, respectively. The inhibitory effect of Ca2+/CaM was attenuated by the CaM antagonists W-7, prenylamine and CaM-kinase II fragment (290-309), but not by the calcineurin inhibitor FK506. Ca2+/CaM also inhibited the labeling of a 135-kDa band (which was considered to be part of N-type Ca2+ channel alpha1 subunits) with 125I-omega-CTX using a cross-linker. These results suggest that Ca2+/CaM affects specific 125I-omega-CTX binding sites, probably N-type Ca2+ channel alpha1 subunits, in crude membranes from chick whole brain.

Surfactant proteins A and D bind CD14 by different mechanisms

Surfactant proteins A (SP-A) and D (SP-D) are lung collectins that are constituents of the innate immune system of the lung. Recent evidence (Sano, H., Sohma, H., Muta, T., Nomura, S., Voelker, D. R., and Kuroki, Y. (1999) J. Immunol. 163, 387-395) demonstrates that SP-A modulates lipopolysaccharide (LPS)-induced cellular responses by direct interaction with CD14. In this report we examined the structural elements of the lung collectins involved in CD14 recognition and the consequences for CD14/LPS interaction. Rat SP-A and SP-D bound CD14 in a concentration-dependent manner. Mannose and EDTA inhibited SP-D binding to CD14 but did not decrease SP-A binding. The SP-A binding to CD14 was completely blocked by a monoclonal antibody that binds to the SP-A neck domain but only partially blocked by an antibody that binds to the SP-A lectin domain. SP-A but not SP-D bound to deglycosylated CD14. SP-D decreased CD14 binding to both smooth and rough LPS, whereas SP-A enhanced CD14 binding to rough LPS and inhibited binding to smooth LPS. SP-A also altered the migration profile of LPS on a sucrose density gradient in the presence of CD14. From these results, we conclude that 1) lung collectins bind CD14, 2) the SP-A neck domain and SP-D lectin domain participate in CD14 binding, 3) SP-A recognizes a peptide component and SP-D recognizes a carbohydrate moiety of CD14, and 4) lung collectins alter LPS/CD14 interactions.

Purification and characterization of bovine cone arrestin (cArr)

To elucidate the quenching mechanism of phototransduction in vertebrate cone photoreceptors, a cDNA clone encoding cone specific arrestin (cArr) was isolated from a bovine retinal cDNA library using a human cArr cDNA probe. Affinity-purified anti-peptide antibody specific to cArr was prepared. Immunohistochemical staining displayed specific labeling of cArr in cone photoreceptors and immunoblotting identified a 46 kDa protein band. We purified cArr from bovine retinas by sequential column chromatography using DEAE-cellulose, gel filtration and mono Q columns. Binding studies revealed no binding of cArr to rhodopsin regardless of whether it was bleached and/or phosphorylated. cArr also failed to bind to heparin-Sepharose under conditions which rod arrestin (rArr) bound to the column. The present data suggest that cArr may play a role in the quenching of phototransduction in cone photoreceptors and that its activity therein is different to that of rArr.

Calcium/calmodulin inhibits the binding of specific [125I]omega-conotoxin GVIA to chick brain membranes

The effect of Ca2+/calmodulin (CaM) on the specific binding of [125I]omega-conotoxin GVIA (125I-omega-CTX) to crude membranes from chick brain was investigated. When we examined the effects of the activation of various endogenous protein kinases on specific [125I]omega-CTX binding to crude membranes, we observed that Ca2+/CaM had an inhibitory effect regardless of whether or not the standard medium contained ATP (0.5 mM). Ca2+/CaM also had an inhibitory effect in a simple binding-assay medium containing HEPES-HCl buffer, BSA, Ca2+ and CaM, and this effect was dependent on the concentration of Ca2+. The effect of Ca2+/CaM was attenuated by the CaM antagonists W-7 and CaM-kinase II fragment (290-309). An experiment with modified ELISA using purified anti omega-CTX antibody indicated that Ca2+/CaM did not affect the direct binding of [125I]omega-CTX and CaM. These results suggest that Ca2+/CaM either directly or indirectly affects specific [125I]omega-CTX binding sites, probably N-type Ca2+ channels in crude membranes from chick whole brain.

Importance of the carboxy-terminal 25 amino acid residues of lung collectins in interactions with lipids and alveolar type II cells

Surfactant proteins A and D (SP-A and SP-D) are structurally related members of the collectin family found in the alveolar compartment of the lung. SP-A binds dipalmitoylphosphatidylcholine (DPPC) and galactosylceramide (GalCer), induces liposome aggregation, and regulates the uptake and secretion of surfactant lipids by alveolar type II cells in vitro. SP-D binds phosphatidylinositol (PI) and glucosylceramide. The purpose of this study was to identify a critical stretch of primary sequence in the SP-A region Cys(204)-Phe(228) and the SP-D region Cys(331)-Phe(355) that is involved in protein-specific lipid and type II cell interactions. Chimeras ad1 and ad2 were constructed with rat SP-A/SP-D splice junctions at Cys(218)/Gly(346) and Lys(203)/Cys(331), respectively. Chimera ad1 but not ad2 retained DPPC liposome binding activity. Both chimeras retained significant binding to GalCer liposomes. Chimera ad1 did not bind to PI, whereas chimera ad2 acquired a significant PI binding. Both chimeras failed to induce liposome aggregation and to interact with alveolar type II cells. In addition, monoclonal antibody 1D6 that blocks specific SP-A functions did not recognize either chimera. From these results, we conclude that (1) the SP-A region Leu(219)-Phe(228) is required for liposome aggregation and interaction with alveolar type II cells, (2) the SP-A region Cys(204)-Cys(218) is required for DPPC binding, (3) the SP-D region Cys(331)-Phe(355) is essential for minimal PI binding, and (4) the epitope for mAb 1D6 is located at the region contiguous to the SP-A region Leu(219)-Phe(228).

Characterization of the Ca2+-dependent binding of annexin IV to surfactant protein A

We have shown previously that surfactant protein A (SP-A) binds to annexin IV in a Ca2+-dependent manner [Sohma, Matsushima, Watanabe, Hattori, Kuroki and Akino (1995) Biochem. J. 312, 175-181]. Annexin IV is a member of the annexin family having four consensus repeats of about 70 amino acids and a unique N-terminal tail. In the present study, the functional site of both annexin IV and SP-A for the Ca2+-dependent binding was investigated using mutant proteins. SP-A bound in a Ca2+-dependent manner to an annexin-IV truncation mutant consisting of the N-terminal domain and the first three domains (T(N-1-2-3)). SP-A also bound to T3-4, but this interaction was not Ca2+-dependent. SP-A bound weakly to the other truncation mutants (T(N-1-2), T(2-3) and T(2-3-4)). Each consensus repeat of annexin IV possesses a conserved acidic amino acid residue (Glu70, Asp142, Glu226 and Asp301) that putatively ligates Ca2+. Using annexin-IV DE mutants in which one, two or three residues out of the four Asp/Glu were altered to Ala by site-directed mutagenesis [Nelson and Creutz (1995) Biochemistry 34, 3121-3132], it was revealed that Ca2+ binding in the third domain is more important than in the other Ca2+-binding sites. SP-A is a member of the animal lectin group homologous with mannose-binding protein A. The substitution of Arg197 of rat SP-A with Asp or Asn eliminated binding to annexin IV, whereas the substitution of Glu195 with Gln was silent. These results suggest that the Ca2+ binding to domain 3 of annexin IV is required for the Ca2+-dependent binding by SP-A and that Arg197 of SP-A is important in this binding.

Pulmonary surfactant protein A modulates the cellular response to smooth and rough lipopolysaccharides by interaction with CD14

Pulmonary surfactant protein A (SP-A) plays an important part in Ab-independent host defense mechanisms of the lung. In this study we investigated how SP-A interacts with distinct serotypes of bacterial LPS and modulates LPS-elicited cellular responses. SP-A bound to rough forms but not to smooth forms of LPS. In the macrophage-like cell line U937, SP-A inhibited mRNA expression and secretion of TNF-alpha induced by smooth LPS, but rough LPS-induced TNF-alpha expression was unaffected by SP-A. When U937 cells and rat alveolar macrophages were preincubated with SP-A, smooth LPS failed to induce TNF-alpha secretion, whereas rough LPS-induced TNF-alpha secretion was modestly increased. To clarify the mechanism by which SP-A modulates LPS-elicited cellular responses, we further examined the interaction of SP-A with CD14, which is known as a major LPS receptor. Western blot analysis revealed that CD14 was one of the SP-A binding proteins isolated from solubilized U937 cells. In addition, SP-A directly bound to recombinant soluble CD14 (rsCD14). When rsCD14 was preincubated with SP-A, the binding of rsCD14 to smooth LPS was significantly reduced but the association of rsCD14 with rough LPS was augmented. These results demonstrate the different actions of SP-A upon distinct serotypes of LPS and indicate that the direct interaction of SP-A with CD14 constitutes a likely mechanism by which SP-A modulates LPS-elicited cellular responses.

Pulmonary Surfactant Protein A Modulates the Cellular Response to Smooth and Rough Lipopolysaccharides by Interaction with CD14

Pulmonary surfactant protein A (SP-A) plays an important part in Ab-independent host defense mechanisms of the lung. In this study we investigated how SP-A interacts with distinct serotypes of bacterial LPS and modulates LPS-elicited cellular responses. SP-A bound to rough forms but not to smooth forms of LPS. In the macrophage-like cell line U937, SP-A inhibited mRNA expression and secretion of TNF-α induced by smooth LPS, but rough LPS-induced TNF-α expression was unaffected by SP-A. When U937 cells and rat alveolar macrophages were preincubated with SP-A, smooth LPS failed to induce TNF-α secretion, whereas rough LPS-induced TNF-α secretion was modestly increased. To clarify the mechanism by which SP-A modulates LPS-elicited cellular responses, we further examined the interaction of SP-A with CD14, which is known as a major LPS receptor. Western blot analysis revealed that CD14 was one of the SP-A binding proteins isolated from solubilized U937 cells. In addition, SP-A directly bound to recombinant soluble CD14 (rsCD14). When rsCD14 was preincubated with SP-A, the binding of rsCD14 to smooth LPS was significantly reduced but the association of rsCD14 with rough LPS was augmented. These results demonstrate the different actions of SP-A upon distinct serotypes of LPS and indicate that the direct interaction of SP-A with CD14 constitutes a likely mechanism by which SP-A modulates LPS-elicited cellular responses.

Introduction of mannose binding protein-type phosphatidylinositol recognition into pulmonary surfactant protein A

Pulmonary surfactant protein A (SP-A) and mannose-binding protein A (MBP-A) are collectins in the C-type lectin superfamily. These collectins exhibit unique lipid binding properties. SP-A binds to dipalmitoyl phosphatidylcholine (DPPC) and galactosylceramide (GalCer) and MBP-A binds to phosphatidylinositol (PI). SP-A also interacts with alveolar type II cells. Monoclonal antibodies (mAbs PE10 and PC6) that recognize human SP-A inhibit the interactions of SP-A with lipids and alveolar type II cells. We mapped the epitopes for anti-human SP-A mAbs by a phage display peptide library. Phage selected by mAbs displayed the consensus peptide sequences that are nearly identical to 184TPVNYTNWYRG194 of human SP-A. The synthetic peptide GTPVNYTNWYRG completely blocked the binding of mAbs to human SP-A. Chimeric proteins were generated in which the rat SP-A region Thr174-Gly194 or the human SP-A region Ser174-Gly194 was replaced with the MBP-A region Thr164-Asp184 (rat ama4 or hu ama4, respectively). The mAbs failed to bind hu ama4. Rat ama4 bound to an affinity matrix on mannose-sepharose but lost all of the SP-A functions except carbohydrate binding and Ca2+-independent GalCer binding. Strikingly, the rat ama4 chimera acquired the PI binding property that MBP-A exhibits. This study demonstrates that the amino acid residues 174-194 of SP-A and the corresponding region of MBP-A are critical for SP-A-type II cell interaction and Ca2+-dependent lipid binding of collectins.

Quantitative reduction of type I adenylyl cyclase in human alcoholics

The amounts of adenylyl cyclase type I (AC I) were examined in various parts of the postmortem brains from alcoholics who prior to death had been abstinent from alcohol for at least 6 months and compared with controls using immunoblot analysis with anti-AC I specific antibody. It was revealed that a significant reduction of AC I was observed in both frontal and temporal cortices. On the other hand, in other areas (occipital cortex, caudate nucleus, putamen, and hippocampus) the amounts were comparable between alcoholics and controls. In the next step, we examined two subtypes of human AC mRNA levels (AC I and AC VIII) in blood cells by quantitative RT-PCR using [alpha-32P]dCTP with two sets of the synthetic oligonucleotide primers based on the DNA sequences reported elsewhere (Villacres, E.C. et al., Genomics 16 (1993) 473-478; J. Parma et al., Biochem. Biophys. Res. Commun. 179 (1991) 455-462). The amounts of amplified DNAs of both AC I and AC VIII were significantly smaller in alcoholics than in controls. On the other hand, the amounts of amplified DNA of beta-actin DNA were almost equal between alcoholics and controls. It appears from these results that a reduction in the amount of AC subtypes may be a biological marker for alcoholics.

Molecular modeling of single polypeptide chain of calcium-binding protein p26olf from dimeric S100B(betabeta)

P26olf from olfactory tissue of frog, which may be involved in olfactory transduction or adaptation, is a Ca2+-binding protein with 217 amino acids. The p26olf molecule contains two homologous parts consisting of the N-terminal half with amino acids 1-109 and the C-terminal half with amino acids 110-217. Each half resembles S100 protein with about 100 amino acids and contains two helix-loop-helix Ca2+-binding structural motifs known as EF-hands: a normal EF-hand at the C-terminus and a pseudo EF-hand at the N-terminus. Multiple alignment of the two S100-like domains of p26olf with 18 S100 proteins indicated that the C-terminal putative EF-hand of each domain contains a four-residue insertion when compared with the typical EF-hand motifs in the S100 protein, while the N-terminal EF-hand is homologous to its pseudo EF-hand. We constructed a three-dimensional model of the p26olf molecule based on results of the multiple alignment and NMR structures of dimeric S100B(betabeta) in the Ca2+-free state. The predicted structure of the p26olf single polypeptide chain satisfactorily adopts a folding pattern remarkably similar to dimeric S100B(betabeta). Each domain of p26olf consists of a unicornate-type four-helix bundle and they interact with each other in an antiparallel manner forming an X-type four-helix bundle between the two domains. The two S100-like domains of p26olf are linked by a loop with no steric hindrance, suggesting that this loop might play an important role in the function of p26olf. The circular dichroism spectral data support the predicted structure of p26olf and indicate that Ca2+-dependent conformational changes occur. Since the C-terminal putative EF-hand of each domain fully keeps the helix-loop-helix motif having a longer Ca2+-binding loop, regardless of the four-residue insertion, we propose that it is a new, novel EF-hand, although it is unclear whether this EF-hand binds Ca2+. P26olf is a new member of the S100 protein family.

The effect of various doses of lazaroid U74389G on lung ischemia reperfusion injury

BACKGROUND

We investigated the effect of lazaroid U74389G, a potent inhibitor of lipid peroxidation, on ischemia-reperfusion injury at three different doses in the rat orthotopic left lung transplantation model.

METHODS

Four groups of reperfused lungs were studied. In group I (control) donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4 degrees C. In groups II, III, and IV, lazaroid was used as an additive to UW solution at concentrations of 30 micromol/L, 50 micromol/L, and 100 micromol/L, respectively, and was also administered intravenously to the recipients 30 minutes before reperfusion after 12 hours of storage in the UW solution at 4 degrees C.

RESULTS

After 1 hour of reperfusion, gas exchange function (p < 0.01), tissue lipid peroxide levels (p < 0.05) and histologic damage in reperfused lung allografts (p< 0.05) were significantly improved in lazaroid-treated group IV compared with control group I.

CONCLUSIONS

These findings suggest that lazaroid U74389G ameliorates ischemia-reperfusion injury in rat lung transplants by inhibiting lipid peroxidation.

Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplant model

We investigated the effect of Lazaroid U74389G on ischemia-reperfusion injury in the rat orthotopic left lung transplantation model. Five groups of reperfused lungs were studied. In group I, donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4C. In groups II, III, and IV, Lazaroid was intravenously administrated at a dose of 1 mg/kg, 8 mg/kg, and 15 mg/kg, respectively, to the donors 30 minutes before preservation and also to the recipients 30 minutes before reperfusion after 12 hours of storage in UW solution at 4C. In group V, Lazaroid was added to the UW solution (80 micromol/l), and also was administered intravenously (6 mg/kg) 30 minutes before reperfusion. After 1 hour of reperfusion, gas exchange function and tissue lipid peroxide levels were significantly improved in Lazaroid-treated groups III, and V compared with no treatment group I. Histologic damage was less severe in groups III, IV, and V than in group I. These findings suggest that Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplants by inhibiting lipid peroxidation, regardless of whether it is administrated intravenously or given as an additive to the preservation solution.

Site-directed mutagenesis of surfactant protein A reveals dissociation of lipid aggregation and lipid uptake by alveolar type II cells

Surfactant protein A (SP-A) binds to dipalmitoylphosphatidylcholine (DPPC) and induces phospholipid vesicle aggregation. It also regulates the uptake and secretion of surfactant lipids by alveolar type II cells. We introduced the single mutations Glu195-->Gln (rE195Q), Lys201-->Ala (rK201A) and Lys203-->Ala (rK203A) for rat SP-A, Arg199-->Ala (hR199A) and Lys201-->Ala (hK201A) for human SP-A, and the triple mutations Arg197, Lys201 and Lys203-->Ala (rR197A/K201A/K203A) for rat SP-A, into cDNAs for SP-A, and expressed the recombinant proteins using baculovirus vectors. All recombinant proteins avidly bound to DPPC liposomes. rE195Q, rK201A, rK203A, hR199A and hK201A function with activity comparable to wild type SP-A. Although rR197A/K201A/K203A was a potent inducer of phospholipid vesicle aggregation, it failed to stimulate lipid uptake. rR197A/K201A/K203A was a weak inhibitor for lipid secretion and did not competed with rat [125I]SP-A for receptor occupancy. From these results, we conclude that Lys201 and Lys203 of rat SP-A, and Arg199 and Lys201 of human SP-A are not individually critical for the interaction with lipids and type II cells, and that Glu195 of rat SP-A can be replaced with Gln without loss of SP-A functions. This study also demonstrates that the SP-A-mediated lipid uptake is not directly correlated with phospholipid vesicle aggregation, and that specific interactions of SP-A with type II cells are involved in the lipid uptake process.