Vegetative fragment production as a means of propagule dispersal for tropical seagrass meadows.

BACKGROUND AND AIMS: Long distance dispersal (LDD) contributes to the replenishment and recovery of tropical seagrass habitats exposed to disturbance, such as cyclones and infrastructure development. However, our current knowledge regarding the physical attributes of seagrass fragments that influence LDD predominantly stems from temperate species and regions. The goal of this paper is to measure seagrass fragment density and viability in two tropical species, assessing various factors influencing their distribution. METHODS: We measured the density and viability of floating seagrass fragments for two tropical seagrass species (Zostera muelleri and Halodule uninervis) in two coastal seagrass meadows in the central Great Barrier Reef World Heritage Area, Australia. We assessed the effect of wind speed, wind direction, seagrass growing/senescent season, seagrass meadow density, meadow location and dugong foraging intensity on fragment density. We also measured seagrass fragment structure and fragment viability; i.e., potential to establish into a new plant. KEY RESULTS: We found that seagrass meadow density, season, wind direction and wind speed influenced total fragment density, while season and wind speed influenced the density of viable fragments. Dugong foraging intensity did not influence fragment density. Our results indicate that wave action from winds combined with high seagrass meadow density increases seagrass fragment creation, and that more fragments are produced during the growing than the senescent season. Seagrass fragments classified as viable for Z. muelleri and H. uninervis had significantly more shoots and leaves than non-viable fragments. We collected 0.63 (±0.08 SE) floating viable fragments 100 m-2 in the growing season, and 0.13 (±0.03 SE) viable fragments 100 m-2 in the senescent season. Over a third (38%) of all fragments collected were viable. CONCLUSION: There is likely to be a large number of viable seagrass fragments available for long distance dispersal. This study's outputs can inform dispersal and connectivity models that are used to direct seagrass ecosystem management and conservation strategies.

Reproductive benefits of no-take marine reserves vary with region for an exploited coral reef fish.

No-take marine reserves (NTMRs) are expected to benefit fisheries via the net export of eggs and larvae (recruitment subsidy) from reserves to adjacent fished areas. Quantifying egg production is the first step in evaluating recruitment subsidy potential. We calculated annual egg production per unit area (EPUA) from 2004 to 2013 for the commercially important common coral trout, Plectropomus leopardus, on fished and NTMR reefs throughout the Great Barrier Reef (GBR), Australia. Geographic region, NTMR status, fish size, and population density were all found to affect EPUA. The interactions among these factors were such that, EPUA on NTMR reefs compared to reefs open to fishing was 21% greater in the southern GBR, 152% greater in the central GBR, but 56% less in the northern GBR. The results show that while NTMRs can potentially provide a substantial recruitment subsidy (central GBR reefs), they may provide a far smaller subsidy (southern GBR), or serve as recruitment sinks (northern GBR) for the same species in nearby locations where demographic rates differ. This study highlights the importance of considering spatial variation in EPUA when assessing locations of NTMRs if recruitment subsidy is expected from them.

Spatial variation in the effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus.

The effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus populations were compared between coral reefs open or closed (no-take marine reserves) to fishing and among four geographic regions of the Great Barrier Reef (GBR), Australia. The specific reproductive metrics investigated were the sex ratio, the proportion of vitellogenic females and the spawning fraction of local populations. Sex ratios became increasingly male biased with length and age, as expected for a protogyne, but were more male biased in southern regions of the GBR (Mackay and Storm Cay) than in northern regions (Lizard Island and Townsville) across all lengths and ages. The proportion of vitellogenic females also increased with length and age. Female P. leopardus were capable of daily spawning during the spawning season, but on average spawned every 4·3 days. Mature females spawned most frequently on Townsville reserve reefs (every 2·3 days) and Lizard Island fished reefs (every 3·2 days). Females on Mackay reefs open to fishing showed no evidence of spawning over 4 years of sampling, while females on reserve reefs spawned only once every 2-3 months. No effect of length on spawning frequency was detected. Spawning frequency increased with age on Lizard Island fished reefs, declined with age on Storm Cay fished reefs, and declined with age on reserve reefs in all regions. It is hypothesized that the variation in P. leopardus sex ratios and spawning frequency among GBR regions is primarily driven by water temperature, while no-take management zones influence spawning frequency depending on the region in which the reserve is located. Male bias and lack of spawning activity on southern GBR, where densities of adult P. leopardus are highest, suggest that recruits may be supplied from central or northern GBR. Significant regional variation in reproductive traits suggests that a regional approach to management of P. leopardus is appropriate and highlights the need for considering spatial variation in reproduction where reserves are used as fishery or conservation management tools.

Mechanisms of action and medicinal applications of abscisic Acid.

Since its discovery in the early 1960's, abscisic acid (ABA) has received considerable attention as an important phytohormone, and more recently, as a candidate medicinal in humans. In plants it has been shown to regulate important physiological processes such as response to drought stress, and dormancy. The discovery of ABA synthesis in animal cells has generated interest in the possible parallels between its role in plant and animal systems. The importance of this molecule has prompted the development of several methods for the chemical synthesis of ABA, which differ significantly from the biosynthesis of ABA in plants through the mevalonic acid pathway. ABA recognition in plants has been shown to occur at both the intra- and extracellularly but little is known about the perception of ABA by animal cells. A few ABA molecular targets have been identified in vitro (e.g., calcium signaling, G protein-coupled receptors) in both plant and animal systems. A unique finding in mammalian systems, however, is that the peroxisome proliferator-activated receptor, PPAR gamma, is upregulated by ABA in both in vitro and in vivo studies. Comparison of the human PPAR gamma gene network with Arabidopsis ABA-related genes reveal important orthologs between these groups. Also, ABA can ameliorate the symptoms of type II diabetes, targeting PPAR gamma in a similar manner as the thiazolidinediones class of anti-diabetic drugs. The use of ABA in the treatment of type II diabetes, offers encouragement for further studies concerning the biomedical applications of ABA.

Increased accuracy of batch fecundity estimates using oocyte stage ratios in Plectropomus leopardus.

Using the ratio of the number of migratory nuclei to hydrated oocytes to estimate batch fecundity of common coral trout Plectropomus leopardus increases the time over which samples can be collected and, therefore, increases the sample size available and reduces biases in batch fecundity estimates.

Regulation of normal cell cycle progression by flavin-containing oxidases.

Mechanisms underlying the role of reactive oxygen species (ROS) generated by flavin-containing oxidases in regulating cell cycle progression were examined in human and rodent fibroblasts. Incubation of confluent cell cultures with nontoxic/nonclastogenic concentrations of the flavoprotein inhibitor, diphenyleneiodonium (DPI), reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase activity and basal ROS levels, but increased proteolysis of cyclin D1, p21(Waf1) and phospho-p38(MAPK). When these cells were allowed to proliferate by subculture in DPI-free medium, an extensive G(1) delay was observed with concomitant activation of p53/p21(Waf1) signaling and reduced phosphorylation of mitogen-activated kinases. Compensation for decreased oxidant generation by simultaneous exposure to DPI and nontoxic doses of the ROS generators, gamma-radiation or t-butyl-hydroperoxide, attenuated the G(1) delay. Whereas the DPI-induced G(1) checkpoint was completely dependent on PHOX91, ATM and WAF1, it was only partially dependent on P53. Interestingly, G(1) to S progression was not affected when another flavin-containing enzyme, nitric oxide synthase, was inhibited nor was it associated with changes in mitochondrial membrane potential. Proliferating cells treated with DPI also experienced a significant but attenuated delay in G(2). We propose that ATM performs a critical function in mediating normal cellular proliferation that is regulated by nonphagocytic NAD(P)H oxidase enzymes activity, which may serve as a novel target for arresting cancer cells in G(1).

Ceramide regulates lipopolysaccharide-induced phosphatidylinositol 3-kinase and Akt activity in human alveolar macrophages.

The phosphatidylinositol (PI) 3-kinase pathway is an important regulator of cell survival. In human alveolar macrophages, we found that LPS activates PI 3-kinase and its downstream effector, Akt. LPS exposure of alveolar macrophages also results in the generation of ceramide. Because ceramide exposure induces apoptosis in other cell types and the PI 3-kinase pathway is known to inhibit apoptosis, we determined the relationship between LPS-induced ceramide and PI 3-kinase activation in alveolar macrophages. We found that ceramide exposure activated PI 3-kinase and Akt. When we blocked LPS-induced ceramide with the inhibitor D609, we blocked LPS-induced PI 3-kinase and Akt activation. Evaluating cell survival after ceramide or LPS exposure, we found that blocking PI 3-kinase induced a significant increase in cell death. Because these effects of PI 3-kinase inhibition were more pronounced in ceramide- vs LPS-treated alveolar macrophages, we also evaluated NF-kappaB, which has also been linked to cell survival. We found that LPS, to a greater degree than ceramide, induced NF-kappaB translocation to the nucleus. As a composite, these studies suggest that the effects of ceramide exposure in alveolar macrophages may be very different from the effects described for other cell types. We believe that LPS induction of ceramide results in PI 3-kinase activation and represents a novel effector mechanism that promotes survival of human alveolar macrophages in the setting of pulmonary sepsis.

GM-CSF increases AP-1 DNA binding and Ref-1 amounts in human alveolar macrophages.

Alveolar macrophages have been implicated in the pathogenesis of a number of acute and chronic lung disorders. A characteristic feature of many of the chronic lung diseases is that the types of macrophages in the lung change, and in most instances, the cells resemble monocyte-like cells. We have previously shown that normal human alveolar macrophages have a decreased capacity to express protein kinase C (PKC)-induced DNA binding activity of the transcription factor activator protein (AP)-1 compared with monocytes. This decrease in AP-1 DNA binding appears to be due to a defect in redox regulation of AP-1 proteins via a decrease in the redox active protein Ref-1. The hypothesis for this study is that there are factors generated during the development of chronic lung disease that increase AP-1 DNA binding activity and Ref-1 production in human alveolar macrophages. We have focused specifically on granulocyte-macrophage colony-stimulating factor (GM-CSF) as a prototype mediator that can be released by alveolar macrophages and is related to the fibrotic process in the lung. We found that after a 24-h incubation with GM-CSF, AP-1 DNA binding was significantly increased in both unstimulated, interleukin (IL)-13, and phorbol myristate acetate (PMA)-stimulated alveolar macrophages and that there was a corresponding increase in Ref-1 protein by Western blot analysis in the PMA-stimulated group. This suggests that disease-related cytokines such as GM-CSF and IL-13 may modulate AP-1 DNA binding activity in alveolar macrophages.

The absence of activator protein 1-dependent gene expression in THP-1 macrophages stimulated with phorbol esters is due to lack of p38 mitogen-activated protein kinase activation.

Activator protein 1 (AP-1) binds to the promoters of many genes involved in immune and inflammatory responses. We have previously shown that the p38 mitogen-activated protein (MAP) kinase regulates NF-kappa B-dependent gene expression by modulating the phosphorylation and subsequent activation of TATA-binding protein (TBP). In this study, we asked whether the p38 MAP kinase regulated the transcriptional activity of AP-1. We found that phorbol 12-myristate 13-acetate (PMA) was unable to drive the AP-1-dependent reporter gene in THP-1 cells. PMA activated both the extracellular signal-regulated kinase and c-Jun NH(2)-terminal kinase MAP kinases, but it did not activate the p38 MAP kinase. We found that cells expressing MAP kinase kinase 6(Glu), which is the upstream kinase that activates the p38 MAP kinase, had significantly increased AP-1-dependent gene expression alone and when stimulated with PMA. These cells also had increased phosphorylation of native c-Jun, suggesting that both c-Jun NH(2)-terminal kinase and p38 MAP kinases phosphorylate c-Jun. More importantly, expression of a constitutive active MAP kinase kinase 6(Glu) resulted in the phosphorylation of a His-TBP fusion protein and increased direct interaction of TBP with c-Jun. These findings suggest that in macrophages, the p38 MAP kinase regulates AP-1-driven transcription by modulating the activation of TBP.

Lipopolysaccharide activates Akt in human alveolar macrophages resulting in nuclear accumulation and transcriptional activity of beta-catenin.

Exposure of human alveolar macrophages to bacterial LPS results in activation of a number of signal transduction pathways. An early event after the alveolar macrophage comes in contact with LPS is activation of the phosphatidylinositol 3 kinase (PI 3-kinase). This study evaluates the downstream effects of that activation. We observed that LPS exposure results in phosphorylation of Akt (serine 473). We found this using both phosphorylation-specific Abs and also by in vivo phosphorylation with (32)P-loaded cells. AKT activation resulted in the phosphorylation-dependent inactivation of glycogen synthase kinase (GSK-3) (serine 21/9). We found that both of these events were linked to PI 3-kinase because the PI 3-kinase inhibitors, wortmannin and LY294002, inhibited LPS-induced phosphorylation of both AKT and GSK-3. Inactivation of GSK-3 has been shown to reduce the ubiquitination of beta-catenin, resulting in nuclear accumulation and transcriptional activity of beta-catenin. Consistent with this, we found that LPS caused an increase in the amounts of PI 3-kinase-dependent nuclear beta-catenin in human alveolar macrophages and expression of genes that require nuclear beta-catenin for their activation. This is the first demonstration that LPS exposure activates AKT, inactivates GSK-3, and causes accumulation and transcriptional activity of beta-catenin in the nucleus of any cell, including alveolar macrophages.

Choroid plexus carcinoma presenting as an intraparenchymal mass.

A 6-year-old girl with a history of a nondisplaced skull fracture diagnosed with computerized tomography (CT) scanning 3 years previously presented with a 6-week history of headaches and decreased use of her right side. On admission CT scans, a large cystic mass was identified in the left frontal lobe region of the brain. A connection between the mass and the ventricular system was not seen on radiological examination or during surgery. Gross-total resection of the mass was achieved. The histological and immunohistochemical findings in the resected tissue confirmed a diagnosis of choroid plexus carcinoma (ChPC). This is the first reported case of a ChPC arising in an extraventricular location not associated with the choroid plexus.

Dental caries in HIV-infected children: a longitudinal study.

PURPOSE: The purpose of this descriptive longitudinal clinical study was to determine primary and permanent dentition caries status in HIV-infected children, and to compare caries status with the CD4 percentage (CD4%) and immune suppression category. MATERIALS AND METHODS: 73 children up to 9 years of age with vertical HIV transmission were evaluated for caries in the primary dentition at baseline and at 6 month intervals over a 30 month period; while 19 HIV-infected children between 5 and 11 years of age had their permanent dentition evaluated for caries at baseline and at 6 month intervals over a 24 month period. Caries status was also compared with CDC CD4 percentage (> 25%, 15-24%, < 15%), and CDC immune suppression categories (immune suppression: none, moderate, severe). With primary dentition caries, comparisons were made among all children (2-9 yr-olds, N = 73), < 2 yr-olds (N = 28), 2 to 4 yr-olds (N = 20), and 5 to 9 yr-olds (N = 25), and compared with NHANES III data. Caries-free status was also determined. RESULTS: During the 30-month period, there was an almost two-fold increase in primary tooth surface caries for the 2 to 9 year-olds. Caries-free status in the primary dentition declined from 60% at baseline to 37% at the 30-month period. With 5 to 11 years-olds, DMFS and DMFT remained relatively stable, while the proportion of caries-free individuals declined from 72% at baseline to 50% at 18 months. Caries in the primary dentition was increased substantially for those in the low CDC CD4 percentage categories and CDC moderate to severe immune suppression categories. CONCLUSION: Primary dentition caries status in HIV-infected children is considerably greater than that for the US pediatric population, and increases with decreasing CD4 percentage and moderate to severe immune suppression. HIV-infected children with caries-free primary dentitions are less frequent than in the US pediatric population, and caries-free status decreases with age, lower CD4 percentage and moderate to severe immune suppression.

Protein kinase C zeta plays a central role in activation of the p42/44 mitogen-activated protein kinase by endotoxin in alveolar macrophages.

Human alveolar macrophages respond to endotoxin (LPS) by activation of a number of mitogen-activated protein kinase pathways, including the p42/44 (extracellular signal-related kinase (ERK)) kinase pathway. In this study, we evaluated the role of the atypical protein kinase C (PKC) isoform, PKC zeta, in LPS-induced activation of the ERK kinase pathway. Kinase activity assays showed that LPS activates PKC zeta, mitogen-activated protein/ERK kinase (MEK, the upstream activator of ERK), and ERK. LPS did not activate Raf-1, the classic activator of MEK. Pseudosubstrate-specific peptides with attached myristic acid are cell permeable and can be used to block the activity of specific PKC isoforms in vivo. We found that a peptide specific for PKC zeta partially blocked activation of both MEK and ERK by LPS. We also found that this peptide blocked in vivo phosphorylation of MEK after LPS treatment. In addition, we found that LPS caused PKC zeta to bind to MEK in vivo. These observations suggest that MEK is an LPS-directed target of PKC zeta. PKC zeta has been shown in other systems to be phosphorylated by phosphatidylinositol (PI) 3-kinase-dependent kinase. We found that LPS activates PI 3-kinase and causes the formation of a PKC zeta/PI 3-kinase-dependent kinase complex. These data implicate the PI 3-kinase pathway as an integral part of the LPS-induced PKC zeta activation. Taken as a whole, these studies suggest that LPS activates ERK kinase, in part, through activation of an atypical PKC isoform, PKC zeta.

A constitutive active MEK --> ERK pathway negatively regulates NF-kappa B-dependent gene expression by modulating TATA-binding protein phosphorylation.

Endotoxin-induced cytokine gene expression is regulated, in part, by NF-kappaB. We have shown that both the ERK and p38 mitogen-activated protein (MAP) kinases are necessary for cytokine gene transcription and that the p38 MAP kinase is required for NF-kappaB-driven transcription, so we hypothesized that the MEK --> ERK pathway regulated NF-kappaB-driven transcription as well. We found that a constitutive active MEK --> ERK pathway inhibited NF-kappaB-driven transcription. In addition, both PD 98059 and a dominant negative ERK2 augmented NF-kappaB-driven transcription; however, neither PD 98059 nor MEK1 altered NF-kappaB activation at any level. The constitutive active MEK --> ERK pathway inhibited the phosphorylation of TBP, which is necessary for both interaction with RelA and binding to the TATA box. Due to the fact that we have shown that the p38 MAP kinase modulates TBP activation, we evaluated the effect of the constitutive active MEK --> ERK pathway on p38 MAP kinase activity. We found that the MEK --> ERK pathway negatively regulates NF-kappaB-driven transcription, in part, by inhibiting p38 MAP kinase activity. Thus, the ERK and p38 MAP kinases have differential effects on NF-kappaB-driven transcription.

Oral manifestations of pediatric vertical HIV infection.

To assess the prevalence and prognostic significance of the history of oral manifestations in children with human immunodeficiency virus infection (HIV), a cohort study of 73 children with vertical HIV infection was conducted. The study subjects were examined every 6 months for oral manifestations. The period prevalence of oral manifestations ranged from a low of 1% for submandibular enlargement and 3% for hairy leukoplakia to a high of 36% for xerostomia and 51% for cervical lymphadenopathy. The occurrence of oral manifestations did not change significantly over time from 1995 to 1998. Finally, the odds of occurrence of cervical lymphadenopathy, xerostomia, and oral candidiasis were greater among children in whom these manifestations had been diagnosed in the preceding 6-18 months than in children without prior diagnosis. Oral manifestations are significant clinical outcomes in pediatric vertical HIV infection, particularly for children diagnosed previously with an oral manifestation.

Activation of ERK2 by respiratory syncytial virus in A549 cells is linked to the production of interleukin 8.

The airway inflammation that results from respiratory syncytial virus infection is associated with a marked increase in interleukin 8 and neutrophils in the infected sites of the lung. In this study, the relationship between production of interleukin 8, infection of A549 cells by the virus, and activation of mitogen-activated protein kinases (MAPKs) was investigated. Infection of A549 cells by the virus caused an increase on the activity of extracellular signal-regulated kinase 2 (ERK2) by about 10-fold compared with the noninfected cells. The increase in the activity of ERK2 during the viral infection was an immediate event and occurred prior to the viral replication process. PD98059, which blocks the activation of MAPK/ERK kinase 1 (MEK1), inhibited the increase in the activity of ERK2 by infection of respiratory syncytial virus by about 50% at 10 microM. Pretreatment of A549 cells with PD98059 before the viral infection also inhibited the increase in the production of interleukin 8 by 50%, but had little effect on the mRNA level. The viral infection had no effect on the activities of p38 and c-jun N-terminal kinase (JNK). These observations suggest that activation of ERK2 by respiratory syncytial virus infection may be one of the mechanisms that result in the increase of the production of interleukin 8.

The p38 mitogen-activated protein kinase is required for NF-kappaB-dependent gene expression. The role of TATA-binding protein (TBP).

Endotoxin-induced cytokine gene transcription in monocytes and macrophages is regulated in part by NF-kappaB. We have previously shown that the p38 mitogen-activated protein (MAP) kinase is necessary for endotoxin-induced cytokine gene transcription. Due to the fact that most cytokine promoter sequences have active NF-kappaB sites, we hypothesized that the p38 MAP kinase was necessary for NF-kappaB-dependent gene expression. We found that NF-kappaB-dependent gene expression was reduced to near control levels with either SB 203580 or a dominant-negative p38 MAP kinase expression vector. Inhibition of the p38 MAP kinase did not alter NF-kappaB activation at any level, but it significantly reduced the DNA binding of TATA-binding protein (TBP) to the TATA box. The dominant-negative p38 MAP kinase expression vector interfered with the direct interaction of native TFIID (TBP) with a co-transfected p65 fusion protein. Likewise, this dominant-negative plasmid also interfered with the direct interaction of a co-transfected TBP fusion protein with the native p65 subunit. The p38 kinase also phosphorylated TFIID (TBP) in vitro, and SB 203580 inhibited phosphorylation of TFIID (TBP) in vivo. Thus, the p38 MAP kinase regulates NF-kappaB-dependent gene transcription, in part, by modulating activation of TFIID (TBP).

Therapy for ventilator-associated pneumonia.

Pneumonia is a serious complication of mechanical ventilation. Pneumonia occurs despite the best efforts at prevention. Multiple methods available to prevent ventilator-associated pneumonia are reviewed, and ventilation-associated pneumonia (VAP) is divided into early versus late onset. The authors discuss the organisms associated with each of these situations, the empiric antibiotic choices, and specific issues related to antibiotic therapy such as resistance, pharmcodynamics, tissue penetration, and types of modifications necessary in empiric choice when the cause of VAP is identified.

Human alveolar macrophages are markedly deficient in REF-1 and AP-1 DNA binding activity.

Although many functions of human alveolar macrophages are altered compared with their precursor cell, the blood monocyte (monocyte), the reason(s) for these functional changes have not been determined. We recently reported that human alveolar macrophages do not express AP-1 DNA binding activity (Monick, M. M., Carter, A. B., Gudmundsson, G., Geist, L. J., and Hunninghake, G. W. (1998) Am. J. Physiol. 275, L389-L397). To determine why alveolar macrophages do not express AP-1 DNA binding activity, we first showed that there was not a decrease in expression of the FOS and JUN proteins that make up the AP-1 complex. There was, however, a significant difference in the amounts of the nuclear protein, REF-1 (which regulates AP-1 DNA binding by altering the redox status of FOS and JUN proteins), in alveolar macrophages compared with monocytes. In addition, in vitro differentiation of monocytes to a macrophage-like cell resulted in decreased amounts of REF-1. Finally, addition of REF-1 from activated monocytes to alveolar macrophage nuclear proteins resulted in a marked increase in AP-1 DNA binding. These studies strongly suggest that the process of differentiation of monocytes into alveolar macrophages is associated with a loss of REF-1 and AP-1 activity. This observation may explain, in part, some of the functional differences observed for alveolar macrophages compared with monocytes.

Both Erk and p38 kinases are necessary for cytokine gene transcription.

A critical feature of sepsis-induced acute lung injury is the release of cytokines from endotoxin (LPS)- stimulated alveolar macrophages (AM). LPS is also known to activate various members of the mitogen- activated protein kinase (MAPK) family in other types of cells. In this study, we evaluated whether multiple members of the MAPK family regulate cytokine gene expression in LPS-stimulated AM. We found that LPS activates both the extracellular signal-regulated kinase (Erk) and p38 kinases, and that this activation is augmented when the cells are cultured in serum. Inhibition of either the Erk (with PD98059) or p38 (with SB203580) kinase pathway resulted in only a partial reduction in cytokine (interleukin-6 and tumor necrosis factor) messenger RNA accumulation and cytokine release, whereas inhibition of both pathways simultaneously resulted in a decrease in cytokine gene expression to near-control levels. Nuclear run-on assays showed that the effect of these MAPK pathways on LPS-induced expression of the cytokine genes was attributable, at least in part, to regulation of gene transcription. These findings suggest that activation of both the Erk and p38 kinase pathways is necessary for optimal cytokine gene expression in LPS-stimulated human AM, and that the MAPK pathways play a critical role in the inflammatory response that occurs in sepsis-induced acute lung injury.