Cooperative Armoring of CAR and TCR T Cells by T Cell-Restricted IL15 and IL21 Universally Enhances Solid Tumor Efficacy

PURPOSE

Chimeric antigen receptor (CAR) and T-cell receptor (TCR) T-cell therapies are effective in a subset of patients with solid tumors, but new approaches are needed to universally improve patient outcomes. Here, we developed a technology to leverage the cooperative effects of IL15 and IL21, two common cytokine-receptor gamma chain family members with distinct, pleiotropic effects on T cells and other lymphocytes, to enhance the efficacy of adoptive T cells.

EXPERIMENTAL DESIGN

We designed vectors that induce the constitutive expression of either membrane-tethered IL15, IL21, or IL15/IL21. We used clinically relevant preclinical models of transgenic CARs and TCRs against pediatric and adult solid tumors to determine the effect of the membrane-tethered cytokines on engineered T cells for human administration.

RESULTS

We found that self-delivery of these cytokines by CAR or TCR T cells prevents functional exhaustion by repeated stimulation and limits the emergence of dysfunctional natural killer (NK)-like T cells. Across different preclinical murine solid tumor models, we observed enhanced regression with each individual cytokine but the greatest antitumor efficacy when T cells were armored with both.

CONCLUSIONS

The coexpression of membrane-tethered IL15 and IL21 represents a technology to enhance the resilience and function of engineered T cells against solid tumors and could be applicable to multiple therapy platforms and diseases. See related commentary by Ruffin et al., p. 1431.

Topoisomerases as anticancer targets

Many cancer type-specific anticancer agents have been developed and significant advances have been made toward precision medicine in cancer treatment. However, traditional or nonspecific anticancer drugs are still important for the treatment of many cancer patients whose cancers either do not respond to or have developed resistance to cancer-specific anticancer agents. DNA topoisomerases, especially type IIA topoisomerases, are proved therapeutic targets of anticancer and antibacterial drugs. Clinically successful topoisomerase-targeting anticancer drugs act through topoisomerase poisoning, which leads to replication fork arrest and double-strand break formation. Unfortunately, this unique mode of action is associated with the development of secondary cancers and cardiotoxicity. Structures of topoisomerase-drug-DNA ternary complexes have revealed the exact binding sites and mechanisms of topoisomerase poisons. Recent advances in the field have suggested a possibility of designing isoform-specific human topoisomerase II poisons, which may be developed as safer anticancer drugs. It may also be possible to design catalytic inhibitors of topoisomerases by targeting certain inactive conformations of these enzymes. Furthermore, identification of various new bacterial topoisomerase inhibitors and regulatory proteins may inspire the discovery of novel human topoisomerase inhibitors. Thus, topoisomerases remain as important therapeutic targets of anticancer agents.

Single-transducer dual-frequency ultrasound generation to enhance acoustic cavitation

Dual- or multiple-frequency ultrasound stimulation is capable of effectively enhancing the acoustic cavitation effect over single-frequency ultrasound. Potential application of this sonoreactor design has been widely proposed such as on sonoluminescence, sonochemistry enhancement, and transdermal drug release enhancement. All currently available sonoreactor designs employed multiple piezoelectric transducers for generating single-frequency ultrasonic waves separately and then these waves were mixed and interfered in solutions. The purpose of this research is to propose a novel design of generating dual-frequency ultrasonic waves with single piezoelectric elements, thereby enhancing acoustic cavitation. Macroscopic bubbles were detected optically, and they were quantified at either a single-frequency or for different frequency combinations for determining their efficiency for enhancing acoustic cavitation. Visible bubbles were optically detected and hydrogen peroxide was measured to quantify acoustic cavitation. Test water samples with different gas concentrations and different power levels were used to determine the efficacy of enhancing acoustic cavitation of this design. The spectrum obtained from the backscattered signals was also recorded and examined to confirm the occurrence of stable cavitation. The results confirmed that single-element dual-frequency ultrasound stimulation can enhance acoustic cavitation. Under certain testing conditions, the generation of bubbles can be enhanced up to a level of five times higher than the generation of bubbles in single-frequency stimulation, and can increase the hydrogen peroxide production up to an increase of one fold. This design may serve as a useful alternative for future sonoreactor design owing to its simplicity to produce dual- or multiple-frequency ultrasound.

Image display for collision avoidance of radiation therapy: treatment planning

Patient treatment in a medical linear accelerator is characterized by many angular and translational movements of the gantry and couch. The direction and orientation of each treatment beam is specified by a set of gantry, turntable, and collimator angles. It is possible that some selected treatment field configurations will result in gantry/couch or gantry/patient collisions that remain undetected during the treatment planning process. In this work, a digital camera has been used to record all the workable gantry/ patient set-up images, and a Windows programming language is used to edit and display these images on a personal computer for the treatment planner to screen the treatment plans. These graphical displays enable the planner to be aware of any potential collision hazards by an actual visualization of each selected gantry/turntable or gantry/patient angle configuration.

Correlates of financial satisfaction

The objectives of this study are to 1) assess the effects of major correlates of global subjective well-being on financial satisfaction, and 2) use empirical data to present the consequences of violating basic regression assumptions. Analyzing data from the General Social Surveys, 1972-1996 (Davis & Smith, 1996a) this study found that among Americans age forty-five and above, most of the major correlates of global subjective well-being show similar effects on financial satisfaction. The study's findings confirm a nonlinear effect of income on financial satisfaction. Comparing results from different analytical methods, this study also alerts researchers to the importance of taking into account the level of measurements of study variables, which have tended to be overlooked by previous subjective well-being research.

Impaired abdominal wall development and deficient wound healing in mice lacking aortic carboxypeptidase-like protein

Aortic carboxypeptidase-like protein (ACLP) is a member of a diverse group of proteins that contain a domain with similarity to that of the Dictyostelium discoideum protein discoidin I. The discoidin domain has been identified in mammalian milk fat globule membrane proteins, blood coagulation factors, and receptor tyrosine kinases, where it may facilitate cell aggregation, adhesion, or cell-cell recognition. Here we show that ACLP is a secreted protein that associates with the extracellular matrix (ECM). During mouse embryogenesis, ACLP is abundantly expressed in the ECM of collagen-rich tissues, including the vasculature, dermis, and the developing skeleton. We deleted the ACLP gene in mice by homologous recombination. The majority of ACLP(-/-) mice die perinatally due to gastroschisis, a severe disruption of the anterior abdominal wall and herniation of the abdominal organs. ACLP(-/-) mice that survived to adulthood developed nonhealing skin wounds. Following injury by a dermal punch biopsy, ACLP(-/-) mice exhibited deficient wound healing compared with controls. In addition, dermal fibroblasts isolated from ACLP(-/-) 18.5-day-postconception embryos exhibited a reduced proliferative capacity compared with wild-type cells. These results indicate that ACLP is an ECM protein that is essential for embryonic development and dermal wound healing processes.

Targeted expression of heme oxygenase-1 prevents the pulmonary inflammatory and vascular responses to hypoxia

Chronic hypoxia causes pulmonary hypertension with smooth muscle cell proliferation and matrix deposition in the wall of the pulmonary arterioles. We demonstrate here that hypoxia also induces a pronounced inflammation in the lung before the structural changes of the vessel wall. The proinflammatory action of hypoxia is mediated by the induction of distinct cytokines and chemokines and is independent of tumor necrosis factor-alpha signaling. We have previously proposed a crucial role for heme oxygenase-1 (HO-1) in protecting cardiomyocytes from hypoxic stress, and potent anti-inflammatory properties of HO-1 have been reported in models of tissue injury. We thus established transgenic mice that constitutively express HO-1 in the lung and exposed them to chronic hypoxia. HO-1 transgenic mice were protected from the development of both pulmonary inflammation as well as hypertension and vessel wall hypertrophy induced by hypoxia. Significantly, the hypoxic induction of proinflammatory cytokines and chemokines was suppressed in HO-1 transgenic mice. Our findings suggest an important protective function of enzymatic products of HO-1 activity as inhibitors of hypoxia-induced vasoconstrictive and proinflammatory pathways.

Akt participation in the Wnt signaling pathway through Dishevelled

Inactivation of glycogen synthase kinase 3beta (GSK3beta) and the resulting stabilization of free beta-catenin are critical steps in the activation of Wnt target genes. While Akt regulates GSK3alpha/beta in the phosphatidylinositide 3-OH kinase signaling pathway, its role in Wnt signaling is unknown. Here we report that expression of Wnt or Dishevelled (Dvl) increased Akt activity. Activated Akt bound to the Axin-GSK3beta complex in the presence of Dvl, phosphorylated GSK3beta and increased free beta-catenin levels. Furthermore, in Wnt-overexpressing PC12 cells, dominant-negative Akt decreased free beta-catenin and derepressed nerve growth factor-induced differentiation. Therefore, Akt acts in association with Dvl as an important regulator of the Wnt signaling pathway.

Trends in financial satisfaction among middle-age and old-age Americans, 1972-1996

Using data from the General Social Surveys (1972-1996), this study decomposes the trends in financial satisfaction into intercohort and intracohort patterns to assess the intracohort change and cohort replacement effects on financial satisfaction. The results suggest that a positive intracohort component of financial satisfaction trends, indicating more financial satisfaction with time; and a negative intercohort component, indicating that younger cohorts are less satisfied financially. The multivariate analysis further suggests that the change in financial satisfaction trends is mostly due to a strong intercohort replacement effect. That is, the change in financial satisfaction trends can be largely accounted for by the intercohort replacement effect of younger cohorts' being less satisfied financially.

CLIF, a novel cycle-like factor, regulates the circadian oscillation of plasminogen activator inhibitor-1 gene expression

The onset of myocardial infarction occurs frequently in the early morning, and it may partly result from circadian variation of fibrinolytic activity. Plasminogen activator inhibitor-1 activity shows a circadian oscillation and may account for the morning onset of myocardial infarction. However, the molecular mechanisms regulating this circadian oscillation remain unknown. Recent evidence indicates that basic helix-loop-helix (bHLH)/PAS domain transcription factors play a crucial role in controlling the biological clock that controls circadian rhythm. We isolated a novel bHLH/PAS protein, cycle-like factor (CLIF) from human umbilical vein endothelial cells. CLIF shares high homology with Drosophila CYCLE, one of the essential transcriptional regulators of circadian rhythm. CLIF is expressed in endothelial cells and neurons in the brain, including the suprachiasmatic nucleus, the center of the circadian clock. In endothelial cells, CLIF forms a heterodimer with CLOCK and up-regulates the PAI-1 gene through E-box sites. Furthermore, Period2 and Cryptochrome1, whose expression show a circadian oscillation in peripheral tissues, inhibit the PAI-1 promoter activation by the CLOCK:CLIF heterodimer. These results suggest that CLIF regulates the circadian oscillation of PAI-1 gene expression in endothelial cells. In addition, the results potentially provide a molecular basis for the morning onset of myocardial infarction.

Striated muscle preferentially expressed genes alpha and beta are two serine/threonine protein kinases derived from the same gene as the aortic preferentially expressed gene-1

Aortic preferentially expressed gene (APEG)-1 is a 1.4-kilobase pair (kb) mRNA expressed in vascular smooth muscle cells and is down-regulated by vascular injury. An APEG-1 5'-end cDNA probe identified three additional isoforms. The 9-kb striated preferentially expressed gene (SPEG)alpha and the 11-kb SPEGbeta were found in skeletal muscle and heart. The 4-kb brain preferentially expressed gene was detected in the brain and aorta. We report here cloning of the 11-kb SPEGbeta cDNA. SPEGbeta encodes a 355-kDa protein that contains two serine/threonine kinase domains and is homologous to proteins of the myosin light chain kinase family. At least one kinase domain is active and capable of autophosphorylation. In the genome, all four isoforms share the middle three of the five exons of APEG-1, and they differ from each other by using different 5'- and 3'-ends and alternative splicing. We show that the expression of SPEGalpha and SPEGbeta is developmentally regulated in the striated muscle during C2C12 myoblast to myotube differentiation in vitro and cardiomyocyte maturation in vivo. This developmental regulation suggests that both SPEGalpha and SPEGbeta can serve as sensitive markers for striated muscle differentiation and that they may be important for adult striated muscle function.

Thioredoxin facilitates the induction of heme oxygenase-1 in response to inflammatory mediators

Heme oxygenase (HO)-1 is a stress response protein that is regulated by oxidative stress. HO-1 catalyzes the generation of biliverdin, carbon monoxide, and iron from heme. Lipopolysaccharide (LPS) and interleukin (IL)-1beta induce HO-1 through the binding of nuclear proteins to AP-1 motifs in enhancer regions upstream from the transcription start site. The DNA binding activity of AP-1 proteins depends on the reduction of cysteines in their DNA-binding domains. We found that agents that disrupt free sulfhydryl groups abolish AP-1 binding activity in nuclear proteins obtained from rat aortic smooth muscle cells and macrophages stimulated with IL-1beta or LPS. Thioredoxin (TRX) may regulate the redox status of nuclear transcription factors in response to oxidative stimuli, thus we determined the role of TRX in the physiologic regulation of HO-1. TRX underwent nuclear translocation in cells stimulated with IL-1beta and LPS. We transfected macrophages with a heterologous promoter construct containing two AP-1 sites from an upstream enhancer region in the HO-1 promoter. Recombinant TRX induced promoter activity to a level analogous to that induced by LPS, and this TRX response was abolished by mutation of the AP-1 sites. An inhibitor of TRX reductase, used to prevent TRX translocation in the reduced state, decreased HO-1 induction by IL-1beta and LPS. These data provide the first evidence that TRX contributes to the induction of HO-1 by inflammatory mediators.

Prevention of hypoxia-induced pulmonary hypertension by enhancement of endogenous heme oxygenase-1 in the rat

We investigated the role of heme oxygenase (HO)-1 in the development of hypoxia-induced pulmonary hypertension. HO catalyzes the breakdown of heme to the antioxidant bilirubin and the vasodilator carbon monoxide. Hypoxia is a potent but transient inducer of HO-1 in vascular smooth muscle cells in vitro and in the lung in vivo. By using agonists of HO-1, we sustained a high expression of HO-1 in the lungs of rats for 1 week. We report that this in vivo enhancement of HO-1 in the lung prevented the development of hypoxic pulmonary hypertension and inhibited the structural remodeling of the pulmonary vessels. The mechanism(s) underlying this effect may involve a direct vasodilating and antiproliferative action of endogenous carbon monoxide, as well as an indirect effect of carbon monoxide on the production of vasoconstrictors. These results provide evidence that enhancement of endogenous adaptive responses may be used to prevent hypoxia-induced pulmonary hypertension.

Cardiovascular basic helix loop helix factor 1, a novel transcriptional repressor expressed preferentially in the developing and adult cardiovascular system

We have cloned a cardiovascular-restricted basic helix-loop-helix factor that interacts with arylhydrocarbon receptor nuclear translocator (ARNT) in a yeast two-hybrid screen. Cardiovascular helix-loop-helix factor 1 (CHF1) is distantly related to the hairy family of transcriptional repressors. We analyzed its expression pattern during mouse embryo development. At day 8.5, the expression of CHF1 is first detected in the primitive ventricle of the primordial heart tube and persists throughout gestation. In rat hearts, this expression is down-regulated after birth, concurrent with terminal differentiation of cardiomyocytes. In the developing vasculature, CHF1 first appears in the dorsal aorta at day 9.0, which precedes the reported expression of smooth muscle cell markers, and persists into adulthood. In an in vitro system of smooth muscle cell differentiation, CHF1 mRNA was barely detectable in undifferentiated cells but was induced highly in differentiated smooth muscle cells. To determine whether CHF1 might affect the function of ARNT, we performed transfection studies. Co-transfection of CHF1 inhibited ARNT/EPAS1-dependent transcription by 85%, and this inhibition is dose-dependent. In electrophoretic mobility studies, CHF1 inhibited the binding of the ARNT/EPAS1 heterodimer to its target site. Our data suggest that CHF1 functions as a transcriptional repressor and may play an important role in cardiovascular development.

Induction of high mobility group I architectural transcription factors in proliferating vascular smooth muscle in vivo and in vitro

Proliferation of vascular smooth muscle cells (VSMCs) is a hallmark of arteriosclerosis. Architectural transcription factors of the high mobility group (HMG)-I family have been implicated in the control of cell proliferation and gene expression. We studied the pattern of HMG-I mRNA and protein expression in proliferating VSMCs. HMG-I(Y) and HMGI-C mRNAs were barely detectable by Northern analysis in samples prepared from uninjured rat carotid arteries. In contrast, these mRNAs were induced dramatically in carotid arteries 2 and 5-6 days after balloon injury. By in situ hybridization at 6 days after injury, the induced mRNAs localized to smooth muscle cells of the developing neointima, and immunocytochemical analysis showed that HMG-I(Y) protein was expressed in the nuclei of these cells. To confirm this association between HMG-I protein induction and cell growth, we assessed HMG-I(Y) and HMGI-C mRNA expression in rat aortic smooth muscle cells (RASMCs) in primary culture. The HMG-I mRNAs were barely detectable in quiescent RASMCs but were induced markedly by serum stimulation. This induction of mRNA by serum was time dependent and peaked at 9 h. Western blot analysis confirmed that HMG-I(Y) protein induction also occurred in vitro. To our knowledge, this is the first demonstration of induction of HMG-I protein expression in proliferating RASMCs in vivo and in vitro. This demonstration suggests that the HMG-I proteins may play an important role in smooth muscle cell proliferation.

Genetic variation at nine STR loci in populations from the Philippines and Thailand living in Taiwan

In order to apply a set of nine STR loci and the amelogenin locus in forensic testing, we have performed a population study on individuals from the Philippines and Thailand living in Taiwan (273 Philippine and 146 Thai individuals were typed by commercially available kits and an automated sequencer). A total of 73 alleles for all systems for both populations could be observed in these two populations. No new intermediate fragments were found. Allele frequencies showed no deviation from Hardy-Weinberg equilibrium. The mean exclusion power (MEP) ranged from 0.327 (TPOX) to 0.706 (FGA), the discriminating power (DP) ranged from 0.790 (TPOX) to 0.963 (FGA) for Philippinos, MEP ranged from 0.247 (TPOX) to 0.723 (FGA), DP ranged from 0.761 (TPOX) to 0.968 (FGA) for Thais, the combined MEP is > 0.9988 and the combined DP is > 0.9999999993 for both Philippinos and Thais.

Generation of a dominant-negative mutant of endothelial PAS domain protein 1 by deletion of a potent C-terminal transactivation domain

Endothelial PAS domain protein 1 (EPAS1) is a basic helix-loop-helix/PAS domain transcription factor that is preferentially expressed in vascular endothelial cells. EPAS1 shares high homology with hypoxia-inducible factor-1alpha (HIF-1alpha) and, like HIF-1alpha, has been shown to bind to the HIF-1-binding site and to activate its downstream genes such as vascular endothelial growth factor (VEGF) and erythropoietin. In this report, we show that EPAS1 increased VEGF gene expression through the HIF-1-binding site. This transactivation was enhanced further by cotransfection of an aryl hydrocarbon receptor nuclear translocator expression plasmid. Deletion analysis of EPAS1 revealed a potent activation domain (amino acids 486-639) essential for EPAS1 to transactivate the VEGF promoter. We confirmed the ability of this domain to activate transcription using a Gal4 fusion protein system. Because a truncated EPAS1 protein lacking the transactivation domain at amino acids 486-639 eliminated induction of the VEGF promoter by wild-type EPAS1, the truncated protein functions as a dominant-negative mutant. Most important, infection of the cells with an adenoviral construct expressing this mutant inhibited the induction of VEGF mRNA under conditions that mimic hypoxia. Our results suggest that EPAS1 is an important regulator of VEGF gene expression. Since VEGF plays a crucial role in angiogenesis, the ability of dominant-negative EPAS1 to inhibit VEGF promoter activity raises the possibility of a novel approach to inhibiting pathological angiogenesis.

Genomic cloning and promoter analysis of aortic preferentially expressed gene-1. Identification of a vascular smooth muscle-specific promoter mediated by an E box motif

Aortic preferentially expressed gene-1 (APEG-1) was originally identified as a 1.4-kilobase (kb) transcript preferentially expressed in differentiated vascular smooth muscle cells (VSMC). Its expression is markedly down-regulated in de-differentiated VSMC, suggesting a role for APEG-1 in VSMC differentiation. We have now determined that APEG-1 is a single-copy gene in the human, rat, and mouse genomes and have mapped human APEG-1 to chromosome 2q34. To study the molecular mechanisms regulating its expression, we characterized the genomic organization and promoter of mouse APEG-1. APEG-1 spans 4.5 kb in the mouse genome and is composed of five exons. Using reporter gene transfection analysis, we found that a 2. 7-kb APEG-1 5'-flanking sequence directed a high level of promoter activity only in VSMC. Its activity was minimal in five other cell types. A repressor region located within an upstream 685-base pair sequence suppressed the activity of this 2.7-kb promoter. Further deletion and mutation analyses identified an E box motif as a positive regulatory element, which was bound by nuclear protein prepared from VSMC. In conjunction with its flanking sequence, this E box motif confers VSMC-specific enhancer activity to a heterologous SV40 promoter. To our knowledge, this is the first demonstration of an E box motif that mediates gene expression restricted to VSMC.

Hypoxia induces severe right ventricular dilatation and infarction in heme oxygenase-1 null mice

Heme oxygenase (HO) catalyzes the oxidation of heme to generate carbon monoxide (CO) and bilirubin. CO increases cellular levels of cGMP, which regulates vascular tone and smooth muscle development. Bilirubin is a potent antioxidant. Hypoxia increases expression of the inducible HO isoform (HO-1) but not the constitutive isoform (HO-2). To determine whether HO-1 affects cellular adaptation to chronic hypoxia in vivo, we generated HO-1 null (HO-1(-/-)) mice and subjected them to hypoxia (10% oxygen) for five to seven weeks. Hypoxia caused similar increases in right ventricular systolic pressure in wild-type and HO-1(-/-) mice. Although ventricular weight increased in wild-type mice, the increase was greater in HO-1(-/-) mice. Similarly, the right ventricles were more dilated in HO-1(-/-) mice. After seven weeks of hypoxia, only HO-1(-/-) mice developed right ventricular infarcts with organized mural thrombi. No left ventricular infarcts were observed. Lipid peroxidation and oxidative damage occurred in right ventricular cardiomyocytes in HO-1(-/-), but not wild-type, mice. We also detected apoptotic cardiomyocytes surrounding areas of infarcted myocardium by terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL) assays. Our data suggest that in the absence of HO-1, cardiomyocytes have a maladaptive response to hypoxia and subsequent pulmonary hypertension. J.Clin. Invest. 103:R23-R29 (1999).

High mobility group-I(Y) protein facilitates nuclear factor-kappaB binding and transactivation of the inducible nitric-oxide synthase promoter/enhancer

Nitric oxide (NO), a free radical gas whose production is catalyzed by the enzyme NO synthase, participates in the regulation of multiple organ systems. The inducible isoform of NO synthase (iNOS) is transcriptionally up-regulated by inflammatory stimuli; a critical mediator of this process is nuclear factor (NF)-kappaB. Our objective was to determine which regulatory elements other than NF-kappaB binding sites are important for activation of the iNOS promoter/enhancer. We also wanted to identify transcription factors that may be functioning in conjunction with NF-kappaB (subunits p50 and p65) to drive iNOS transcription. Deletion analysis of the iNOS promoter/enhancer revealed that an AT-rich sequence (-61 to -54) downstream of the NF-kappaB site (-85 to -76) in the 5'-flanking sequence was important for iNOS induction by interleukin-1beta and endotoxin in vascular smooth muscle cells. This AT-rich sequence, corresponding to an octamer (Oct) binding site, bound the architectural transcription factor high mobility group (HMG)-I(Y) protein. Electrophoretic mobility shift assays showed that HMG-I(Y) and NF-kappaB subunit p50 bound to the iNOS promoter/enhancer to form a ternary complex. The formation of this complex required HMG-I(Y) binding at the Oct site. The location of an HMG-I(Y) binding site typically overlaps that of a recruited transcription factor. In the iNOS promoter/enhancer, however, HMG-I(Y) formed a complex with p50 while binding downstream of the NF-kappaB site. Furthermore, overexpression of HMG-I(Y) potentiated iNOS promoter/enhancer activity by p50 and p65 in transfection experiments, suggesting that HMG-I(Y) contributes to the transactivation of iNOS by NF-kappaB.

Induction of high mobility group-I(Y) protein by endotoxin and interleukin-1beta in vascular smooth muscle cells. Role in activation of inducible nitric oxide synthase

Nonhistone chromosomal proteins of the high mobility group (HMG) affect the transcriptional regulation of certain mammalian genes. For example, HMG-I(Y) controls cytokine-mediated promoters that require transcription factors, such as nuclear factor-kappaB, for maximal expression. Even though a great deal is known about how HMG-I(Y) facilitates expression of other genes, less is known about the regulation of HMG-I(Y) itself, especially in cells in primary culture. Therefore we investigated the effect of endotoxin and the cytokine interleukin-1beta on HMG-I(Y) expression in vascular smooth muscle cells. Induction of HMG-I(Y) peaked after 48 h of interleukin-1beta stimulation (6.2-fold) in cells in primary culture, and this increase in mRNA corresponded to an increase in HMG-I(Y) protein. Moreover, immunohistochemical staining revealed a dramatic increase in HMG-I(Y) protein expression in vascular smooth muscle cells after endotoxin stimulation in vivo. This increase in HMG-I(Y) expression (both in vitro and in vivo) mirrored an up-regulation of inducible nitric oxide synthase, a cytokine-responsive gene. The functional significance of this coinduction is underscored by our finding that HMG-I(Y) potentiated the response of inducible nitric oxide synthase to nuclear factor-kappaB transactivation. Taken together, these studies suggest that induction of HMG-I(Y), and subsequent transactivation of iNOS, may contribute to a reduction in vascular tone during endotoxemia and other systemic inflammatory processes.

Embryonic expression suggests an important role for CRP2/SmLIM in the developing cardiovascular system

Proteins of the LIM family are critical regulators of development and differentiation in various cell types. We have described the cloning of cysteine-rich protein 2/smooth muscle LIM protein (CRP2/SmLIM), a LIM-only protein expressed in differentiated vascular smooth muscle cells. As a first step toward understanding the potential functions of CRP2/SmLIM, we analyzed its expression after gastrulation in developing mice and compared the expression of CRP2/SmLIM with that of the other 2 members of the CRP subclass, CRP1 and CRP3/MLP. In situ hybridization in whole-mount and sectioned embryos showed that CRP2/SmLIM was expressed in the sinus venosus and the 2 cardiac chambers at embryonic day 9. Vascular expression of CRP2/SmLIM was first seen at embryonic day 10. At subsequent time points, CRP2/SmLIM expression decreased in the heart but remained high in the vasculature. CRP1 was expressed both in vascular and nonvascular tissues containing smooth muscle cells, whereas CRP3/MLP was expressed only in tissues containing striated muscle. These patterns of expression were maintained in the adult animal and suggest an important role for this gene family in the development of smooth and striated muscle.

Validity and reliability of the Leisure Assessment Inventory

The validity and reliability of the Leisure Assessment Inventory, a tool developed to measure leisure behavior as it applies to adults with mental retardation, was examined. Leisure behavior was assessed using four indexes: Leisure Activity Participation, Leisure Preference, Leisure Interest, and Leisure Constraints. The inventory was administered to 92 adults, ages 30 and older, with mild to moderate mental retardation. Two indexes (Leisure Activity Participation and Leisure Interest) demonstrated higher reliability from test to retest whereas the remaining two (Leisure Preference and Leisure Constraints) showed only moderate consistency. Overall findings provide evidence of the inventory's stability, consistency, convergent and discriminant validity, and construct validity.