Association of Follow-up Blood Cultures With Mortality in Patients With Gram-Negative Bloodstream Infections: A Systematic Review and Meta-analysis.

Importance: Obtaining follow-up blood cultures (FUBCs) in patients with Staphylococcus aureus bloodstream infection (BSI) is standard practice, although its utility in patients with gram-negative bacterial BSI (GN-BSI) is unclear. Objective: To examine whether obtaining FUBCs is associated with decreased mortality (key question [KQ] 1) and whether positive vs negative FUBCs are associated with increased mortality (KQ2). Data Sources: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and gray literature were searched from inception to March 11, 2022. Study Selection: Two investigators used predefined eligibility criteria to independently screen titles, abstracts, and relevant full texts. Randomized clinical trials or observational studies that matched or statistically adjusted for differences in, at minimum, level of acute illness between patients in the intervention (eg, FUBCs obtained) and control (eg, FUBCs not obtained) groups were included in primary analyses. Articles published in languages other than English were excluded. Data Extraction and Synthesis: Data abstraction and quality assessments were performed by one investigator and verified by a second investigator. Risk of bias was assessed with the Newcastle-Ottawa Scale. Effect sizes were pooled using random-effects models. The study followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline. Main Outcomes and Measures: Mortality before hospital discharge or up to 30 days from the index blood culture. Results: From 3495 studies, 15 were included (all nonrandomized). In the 5 studies (n = 4378 patients) that met criteria for the KQ1 primary analysis, obtaining FUBCs was associated with decreased mortality (hazard ratio, 0.56; 95% CI, 0.45-0.71). For KQ2, 2 studies met criteria for the primary analysis (ie, matched or statistically adjusted for differences in patients with positive vs negative FUBCs), so an exploratory meta-analysis of all 9 studies that investigated KQ2 (n = 3243 patients) was performed. Positive FUBCs were associated with increased mortality relative to negative blood cultures (odds ratio, 2.27; 95% CI, 1.54-3.34). Limitations of the literature included a lack of randomized studies and few patient subgroup analyses. Conclusions and Relevance: In this systematic review and meta-analysis, obtaining FUBCs in patients with GN-BSI was associated with decreased mortality. The benefit of FUBCs may stem from identification of patients with positive FUBCs, which was a poor prognostic marker.

Differentiation Trajectory of Limbal Stem and Progenitor Cells under Normal Homeostasis and upon Corneal Wounding.

Limbal stem cells (LSCs) reside discretely at limbus surrounded by niche cells and progenitor cells. The aim of this study is to identify the heterogeneous cell populations at limbus under normal homeostasis and upon wounding using single-cell RNA sequencing in a mouse model. Two putative LSC types were identified which showed a differentiation trajectory into limbal progenitor cell (LPC) types under normal homeostasis and during wound healing. They were designated as "putative active LSCs" and "putative quiescent LSCs", respectively, because the former type actively divided upon wounding while the later type stayed at a quiescent status upon wounding. The "putative quiescent LSCs" might contribute to a barrier function due to their characteristic markers regulating vascular and epithelial barrier and growth. Different types of LPCs at different proliferative statuses were identified in unwounded and wounded corneas with distinctive markers. Four maturation markers (Aldh3, Slurp1, Tkt, and Krt12) were screened out for corneal epithelium, which showed an increased expression along the differentiation trajectory during corneal epithelial maturation. In conclusion, our study identified two different types of putative LSCs and several types of putative LPCs under normal homeostasis and upon wounding, which will facilitate the understanding of corneal epithelial regeneration and wound healing.

IL-11 Induces Encephalitogenic Th17 Cells in Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis.

IL-11+CD4+ cells accumulate in the cerebrospinal fluid of patients with early relapsing-remitting multiple sclerosis (MS) and in active brain MS lesions. Mouse studies have confirmed a causal role of IL-11 in the exacerbation of relapsing-remitting experimental autoimmune encephalomyelitis (RREAE). Administration of IL-11 at the time of clinical onset of RREAE induced an acute exacerbation and increased clinical scores, which persisted during the entire course of the disease. IL-11 increased the numbers of spinal cord inflammatory foci, as well as the numbers of peripheral and CNS-infiltrating IL-17+CD4+ cells and IL-17A serum levels. Ag recall assays revealed that IL-11 induces IL-17A+, GM-CSF+, and IL-21+CD4+ myelin Ag-reactive cells. Passive transfer of these encephalitogenic CD4+ T cells induced severe RREAE with IL-17A+CCR6+ CD4+ and B cell accumulation within the CNS. Furthermore, passive transfer of nonmanipulated CNS-derived mononuclear cells from mice with RREAE after a single dose of IL-11 induced severe RREAE with increased accumulation of IL-17A+ and CCR6+ CD4+ cells within the CNS. These results suggest that IL-11 might serve as a biomarker of early autoimmune response and a selective therapeutic target for patients with early relapsing-remitting MS.

A Phosphomimetic Mutation Stabilizes SOD1 and Rescues Cell Viability in the Context of an ALS-Associated Mutation.

The majority of amyotrophic lateral sclerosis (ALS)-related mutations in the enzyme Cu,Zn superoxide dismutase (SOD1), as well as a post-translational modification, glutathionylation, destabilize the protein and lead to a misfolded oligomer that is toxic to motor neurons. The biophysical role of another physiological SOD1 modification, T2-phosphorylation, has remained a mystery. Here, we find that a phosphomimetic mutation, T2D, thermodynamically stabilizes SOD1 even in the context of a strongly SOD1-destabilizing mutation, A4V, one of the most prevalent and aggressive ALS-associated mutations in North America. This stabilization protects against formation of toxic SOD oligomers and positively impacts motor neuron survival in cellular assays. We solve the crystal structure of T2D-SOD1 and explain its stabilization effect using discrete molecular dynamics (DMD) simulations. These findings imply that T2-phosphorylation may be a plausible innate cellular protection response against SOD1-induced cytotoxicity, and stabilizing the SOD1 native conformation might offer us viable pharmaceutical strategies against currently incurable ALS.

Toll-like receptor (TLR)7 and TLR9 agonists enhance interferon (IFN) beta-1a's immunoregulatory effects on B cells in patients with relapsing-remitting multiple sclerosis (RRMS).

We report that B cells from patients with RRMS have decreased endogenous IFN-ß secretion and deficient IFN receptor (IFNAR)1/2 and TLR7 gene expression in comparison to healthy controls (HCs), which may contribute to disregulation of cytokine secretion by B cells. We propose that TLR7 and TLR9 stimulation with loxorubin (LOX) and CpG, in combination with exogenous IFN-ß may effectively reconstitute endogenous IFN-ß production deficit and induce the secretion of immunoregulatory cytokines by B cells. Both LOX/IFN-ß and CpG/IFN-ß in-vitro treatments of B cells from RRMS patients induced higher endogenous IFN-ß gene expression in comparison to the exogenous IFN-ß alone. CpG/IFN-ß combination induced higher secretion of IL-10, TGF-ß, and IL-27 in comparison to stimulation with IFN-ß. Our study provides a basis for future clinical studies employing IFN-ß and TLR7/9 agonists, which may enhance the resolution of the inflammatory response in RRMS.

Nonnative SOD1 trimer is toxic to motor neurons in a model of amyotrophic lateral sclerosis.

Since the linking of mutations in the Cu,Zn superoxide dismutase gene (sod1) to amyotrophic lateral sclerosis (ALS) in 1993, researchers have sought the connection between SOD1 and motor neuron death. Disease-linked mutations tend to destabilize the native dimeric structure of SOD1, and plaques containing misfolded and aggregated SOD1 have been found in the motor neurons of patients with ALS. Despite advances in understanding of ALS disease progression and SOD1 folding and stability, cytotoxic species and mechanisms remain unknown, greatly impeding the search for and design of therapeutic interventions. Here, we definitively link cytotoxicity associated with SOD1 aggregation in ALS to a nonnative trimeric SOD1 species. We develop methodology for the incorporation of low-resolution experimental data into simulations toward the structural modeling of metastable, multidomain aggregation intermediates. We apply this methodology to derive the structure of a SOD1 trimer, which we validate in vitro and in hybridized motor neurons. We show that SOD1 mutants designed to promote trimerization increase cell death. Further, we demonstrate that the cytotoxicity of the designed mutants correlates with trimer stability, providing a direct link between the presence of misfolded oligomers and neuron death. Identification of cytotoxic species is the first and critical step in elucidating the molecular etiology of ALS, and the ability to manipulate formation of these species will provide an avenue for the development of future therapeutic strategies.

Immunologic and MRI markers of the therapeutic effect of IFN-ß-1a in relapsing-remitting MS.

OBJECTIVES: To assess potential roles of effector cells and immunologic markers in demyelinating CNS lesion formation, and their modulation by interferon ß-1a (IFN-ß-1a). METHODS: Twenty-three patients with relapsing-remitting multiple sclerosis (RRMS) received IFN-ß-1a for 6 months. Immunologic marker results were correlated with brain MRI lesion volumes, and volumes of normal-appearing brain tissue (NABT) with decreasing or increasing voxel-wise magnetization transfer ratio (VW-MTR), suggestive of demyelination and remyelination, respectively. RESULTS: Baseline expression of Th22 cell transcription factor aryl hydrocarbon receptor (AHR) and interleukin (IL)-17F, and percentages of IL-22-expressing CD4(+) and CD8(+) cells, were significantly higher in patients vs 15 healthy controls; IL-4 in CD4(+) cells was lower. Baseline percentage of IL-22-producing CD8(+) cells positively correlated with T2 lesion volumes, while percentage of IL-17A-producing CD8(+) cells positively correlated with T2 and T1 lesion volumes. IFN-ß-1a induced reductions in transcription factor AHR, T-bet, and retinoic acid-related orphan nuclear hormone receptor C (RORc) gene expression, while it increased GATA3's expression in CD4(+) cells. Percentages of IL-22-, IL-17A-, and IL-17F-expressing T cells significantly decreased following treatment. Increased percentages of IL-10-expressing CD4(+) and CD8(+) cells correlated with greater NABT volume with increasing VW-MTR, while decreased percentage of IL-17F-expressing CD4(+) cells positively correlated with decreased NABT volume with decreasing VW-MTR. CONCLUSIONS: Findings indicate that IFN-ß-1a suppresses Th22 and Th17 cell responses, which were associated with decreased MRI-detectable demyelination. CLASSIFICATION OF EVIDENCE: This pilot study provides Class III evidence that reduced Th22 and Th17 responses are associated with decreased demyelination following IFN-ß-1a treatment in patients with RRMS.

Immunological and short-term brain volume changes in relapsing forms of multiple sclerosis treated with interferon beta-1a subcutaneously three times weekly: an open-label two-arm trial.

BACKGROUND: Brain volume atrophy is observed in relapsing-remitting multiple sclerosis (RRMS). METHODS: Brain volume changes were evaluated in 23 patients with RRMS treated with interferon ß-1a 44 µg given subcutaneously (SC) three times a week (tiw) and 15 healthy controls. Percentages of whole brain and tissue-specific volume change were measured from baseline (0 months) to 3 months, from 3 to 6 months, and from baseline to 6 months using SIENAX Multi Time Point (SX-MTP) algorithms. Immunological status of patients was also determined and correlations between subsets of T cells and changes in brain volume were assessed. RESULTS: Interferon ß-1a 44 µg SC tiw in 23 patients with RRMS resulted in significant reductions in whole brain and gray matter tissue volume early in the treatment course (baseline to 3 months; mean change; -0.95%; P = 0.030, -1.52%; P = 0.004, respectively), suggesting a short-term treatment-induced pseudoatrophy effect. From baseline to 6 months, there were significant correlations observed between decreased T- cell expression of IL-17 F and decreased whole brain and brain tissue-specific volume. CONCLUSIONS: These findings are consistent with the interpretation of the pseudoatrophy effect as resolution of inflammation following treatment initiation with interferon ß-1a 44 µg SC tiw, rather than disease-related tissue loss. TRIAL REGISTRATION: ClinicalTrials.gov; NCT01085318.

IL-11 Induces Th17 Cell Responses in Patients with Early Relapsing-Remitting Multiple Sclerosis.

Clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS) is the earliest clinically evident phase of the disease, which may provide valuable insight into the molecular mechanisms of the initiation of the autoimmune response in MS. Our results introduce IL-11 as a new cytokine that plays a role in the autoimmune response in the early phase of the disease. IL-11 is the highest upregulated cytokine in the sera and cerebrospinal fluid from CIS patients, which is also increased in patients with clinically definitive relapsing-remitting MS in comparison with healthy control subjects. Serum IL-11 levels are significantly increased during clinical exacerbations in comparison with remissions in the same patients. CD4(+) cells represent a predominant cell source of IL-11 in the peripheral circulation, and the percentage of IL-11(+)CD4(+) cells is significantly increased in CIS patients in comparison with healthy control subjects. Furthermore, we have identified IL-11 as a new Th17-promoting cytokine, because it induces a differentiation of naive CD4(+) T cells into Th17 cells, as well as expansion of Th17 memory cells. Because the Th17 cytokines IL-17F, IL-21 and TNF-α, and TGF-ß induce differentiation of naive cells in the IL-11-secreting CD4(+) cells, we propose that cross-talk between IL-11(+)CD4(+) and Th17 cells may play a role in the inflammatory response in relapsing-remitting MS.

The role of endogenous IFN-ß in the regulation of Th17 responses in patients with relapsing-remitting multiple sclerosis.

IFN-ß has been used as a first-line therapy for relapsing-remitting multiple sclerosis (RRMS). Because only a few studies have addressed the role of endogenous IFN-ß in the pathogenesis of the disease, our objective was to characterize its role in the transcriptional regulation of pathogenic Th17 cytokines in patients with RRMS. In vitro studies have demonstrated that IFN-ß inhibits IL-17A, IL-17F, IL-21, IL-22, and IFN-γ secretion in CD4(+) lymphocytes through the induction of suppressor of cytokine secretion 1 and suppressor of cytokine secretion 3. We found that patients with RRMS have increased serum and cerebrospinal fluid Th17 (IL-17A and IL-17F) cytokine levels in comparison with the control subjects, suggesting that deficient endogenous IFN-ß secretion or signaling can contribute to the dysregulation of those pathogenic cytokines in CD4(+) cells. We identified that the endogenous IFN-ß from serum of RRMS patients induced a significantly lower IFN-inducible gene expression in comparison with healthy controls. In addition, in vitro studies have revealed deficient endogenous and exogenous IFN-ß signaling in the CD4(+) cells derived from patients with MS. Interestingly, upon inhibition of the endogenous IFN-ß signaling by silencing IFN regulatory factor (IRF) 7 gene expression, the resting CD4(+) T cells secreted significantly higher level of IL-17A, IL-17F, IL-21, IL-22, and IL-9, suggesting that endogenous IFN-ß suppresses the secretion of these pathogenic cytokines. In vivo recombinant IFN-ß-1a treatment induced IFNAR1 and its downstream signaling molecules' gene expression, suggesting that treatment reconstitutes a deficient endogenous IFN-ß regulation of the CD4(+) T cells' pathogenic cytokine production in patients with MS.

Differential reconstitution of T cell subsets following immunodepleting treatment with alemtuzumab (anti-CD52 monoclonal antibody) in patients with relapsing-remitting multiple sclerosis.

Alemtuzumab (anti-CD52 mAb) provides long-lasting disease activity suppression in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to characterize the immunological reconstitution of T cell subsets and its contribution to the prolonged RRMS suppression following alemtuzumab-induced lymphocyte depletion. The study was performed on blood samples from RRMS patients enrolled in the CARE-MS II clinical trial, which was recently completed and led to the submission of alemtuzumab for U.S. Food and Drug Administration approval as a treatment for RRMS. Alemtuzumab-treated patients exhibited a nearly complete depletion of circulating CD4(+) lymphocytes at day 7. During the immunological reconstitution, CD4(+)CD25(+)CD127(low) regulatory T cells preferentially expanded within the CD4(+) lymphocytes, reaching their peak expansion at month 1. The increase in the percentage of TGF-ß1-, IL-10-, and IL-4-producing CD4(+) cells reached a maximum at month 3, whereas a significant decrease in the percentages of Th1 and Th17 cells was detected at months 12 and 24 in comparison with the baseline. A gradual increase in serum IL-7 and IL-4 and a decrease in IL-17A, IL-17F, IL-21, IL-22, and IFN-γ levels were detected following treatment. In vitro studies have demonstrated that IL-7 induced an expansion of CD4(+)CD25(+)CD127(low) regulatory T cells and a decrease in the percentages of Th17 and Th1 cells. In conclusion, our results indicate that differential reconstitution of T cell subsets and selectively delayed CD4(+) T cell repopulation following alemtuzumab-induced lymphopenia may contribute to its long-lasting suppression of disease activity.

Simvastatin inhibits secretion of Th17-polarizing cytokines and antigen presentation by DCs in patients with relapsing remitting multiple sclerosis.

Statins, widely used cholesterol-lowering agents, have also been demonstrated to have antiinflammatory effects. Here, we characterize the capacity of simvastatin to target DCs and modulate T-cell priming and Th17-cell differentiation, in a cohort of patients with relapsing remitting multiple sclerosis (RRMS). We report that simvastatin inhibits IL-1ß, IL-23, TGF-ß, IL-21, IL-12p70, and induces IL-27 secretion from DCs in RRMS patients, providing an inhibitory cytokine milieu for Th17 and Th1-cell differentiation. The effect on DCs is mediated via induction of SOCS1, SOCS3, and SOCS7 gene expression, which are associated with the inhibition of STAT1, STAT3, and ERK1/2 phosphorylation. A geranylgeranyl transferase inhibitor replicated simvastatin's effects on DC cytokine secretion, implicating that simvastatin-induced depletion of isoprenoids mediates this effect. Simvastatin inhibited antigen presentation by DCs via suppression of the MHC class I expression, costimulatory molecules CD80 and CD40, and by inducing a dramatic loss of dendritic processes. The changes in DC morphology were also mediated via inhibition of geranylgeranylation. The therapeutic use of geranylgeranylation inhibitors may provide selective inhibition of key pathogenic cytokines that drive the autoimmune response in MS; their use represents a promising therapeutic approach that requires further clinical testing.

CIP, a cardiac Isl1-interacting protein, represses cardiomyocyte hypertrophy.

RATIONALE: Mammalian heart has minimal regenerative capacity. In response to mechanical or pathological stress, the heart undergoes cardiac remodeling. Pressure and volume overload in the heart cause increased size (hypertrophic growth) of cardiomyocytes. Whereas the regulatory pathways that activate cardiac hypertrophy have been well-established, the molecular events that inhibit or repress cardiac hypertrophy are less known. OBJECTIVE: To identify and investigate novel regulators that modulate cardiac hypertrophy. METHODS AND RESULTS: Here, we report the identification, characterization, and functional examination of a novel cardiac Isl1-interacting protein (CIP). CIP was identified from a bioinformatic search for novel cardiac-expressed genes in mouse embryonic hearts. CIP encodes a nuclear protein without recognizable motifs. Northern blotting, in situ hybridization, and reporter gene tracing demonstrated that CIP is highly expressed in cardiomyocytes of developing and adult hearts. Yeast two-hybrid screening identified Isl1, a LIM/homeodomain transcription factor essential for the specification of cardiac progenitor cells in the second heart field, as a cofactor of CIP. CIP directly interacted with Isl1, and we mapped the domains of these two proteins, which mediate their interaction. We show that CIP represses the transcriptional activity of Isl1 in the activation of the myocyte enhancer factor 2C. The expression of CIP was dramatically reduced in hypertrophic cardiomyocytes. Most importantly, overexpression of CIP repressed agonist-induced cardiomyocyte hypertrophy. CONCLUSIONS: Our studies therefore identify CIP as a novel regulator of cardiac hypertrophy.

The histone methyltransferase Set7/9 promotes myoblast differentiation and myofibril assembly.

The molecular events that modulate chromatin structure during skeletal muscle differentiation are still poorly understood. We report in this paper that expression of the H3-K4 histone methyltransferase Set7 is increased when myoblasts differentiate into myotubes and is required for skeletal muscle development, expression of muscle contractile proteins, and myofibril assembly. Knockdown of Set7 or expression of a dominant-negative Set7 mutant impairs skeletal muscle differentiation, accompanied by a decrease in levels of histone monomethylation (H3-K4me1). Set7 directly interacts with MyoD to enhance expression of muscle differentiation genes. Expression of myocyte enhancer factor 2 and genes encoding contractile proteins is decreased in Set7 knockdown myocytes. Furthermore, we demonstrate that Set7 also activates muscle gene expression by precluding Suv39h1-mediated H3-K9 methylation on the promoters of myogenic differentiation genes. Together, our experiments define a biological function for Set7 in muscle differentiation and provide a molecular mechanism by which Set7 modulates myogenic transcription factors during muscle differentiation.

Simvastatin inhibits IFN regulatory factor 4 expression and Th17 cell differentiation in CD4+ T cells derived from patients with multiple sclerosis.

Subsequent to the clinical trial of simvastatin in patients with relapsing remitting multiple sclerosis (RR MS), which demonstrated the ability of simvastatin to inhibit new inflammatory CNS lesion formation, the current in vitro study has characterized the mechanisms through which simvastatin inhibits Th17 cell differentiation. The anti-inflammatory effects of statins are mediated by the inhibition of isoprenylation, which ensures proper membrane insertion and function of proteins. Small GTPases, involved in multiple signal transduction pathways, are the key targets for isoprenylation. We report that simvastatin, one of the most hydrophobic statins with good CNS penetration, inhibited Th17 cell differentiation and IL-17A, IL-17F, IL-21, and IL-22 secretion in in vitro-differentiated naive CD4(+) T cells from RR MS patients. Simvastatin exerted a less prominent effect on the cells from healthy controls, as it inhibited only IL-17F secretion. The inhibition of Th17 cell differentiation was mediated via inhibition of IFN regulatory factor 4 (IRF4) expression, which was identified as a key transcription factor for human Th17 cell differentiation using both IRF4 gene knockdown and overexpression experiments. In studies addressing which isoprenylation pathway--geranylgeranylation or farnesylation--is inhibited by simvastatin, we demonstrated that the geranylgeranyl transferase inhibitor replicated the effect of simvastatin. Selective inhibition of geranylgeranylated RhoA-associated kinase replicated the effect of simvastatin on the inhibition of IRF4 expression and IL-17A, IL-17F, IL-21, and IL-22 secretion, presenting a promising new therapeutic approach for this disabling disease.

microRNA-1 and microRNA-206 regulate skeletal muscle satellite cell proliferation and differentiation by repressing Pax7.

Skeletal muscle satellite cells are adult stem cells responsible for postnatal skeletal muscle growth and regeneration. Paired-box transcription factor Pax7 plays a central role in satellite cell survival, self-renewal, and proliferation. However, how Pax7 is regulated during the transition from proliferating satellite cells to differentiating myogenic progenitor cells is largely unknown. In this study, we find that miR-1 and miR-206 are sharply up-regulated during satellite cell differentiation and down-regulated after muscle injury. We show that miR-1 and miR-206 facilitate satellite cell differentiation by restricting their proliferative potential. We identify Pax7 as one of the direct regulatory targets of miR-1 and miR-206. Inhibition of miR-1 and miR-206 substantially enhances satellite cell proliferation and increases Pax7 protein level in vivo. Conversely, sustained Pax7 expression as a result of the loss of miR-1 and miR-206 repression elements at its 3' untranslated region significantly inhibits myoblast differentiation. Therefore, our experiments suggest that microRNAs participate in a regulatory circuit that allows rapid gene program transitions from proliferation to differentiation.

Isolation and analysis of water stress induced genes in maize seedlings by subtractive PCR and cDNA macroarray.

In order to identify genes induced during the water stress response in maize (Zea mays) seedlings, suppression subtractive hybridization (SSH) was performed using mixed cDNAs prepared from maize seedlings treated with 20% PEG as testers and cDNAs from unstressed maize seedlings as drivers. A forward subtractive cDNA library was constructed, from which 960 recombinant colonies were picked and amplified. Through differential screening of the subtractive cDNA library, 533 clones were identified as water stress induced. After sequencing, 190 unique expressed sequence tags (ESTs) were obtained by clustering and blast analysis, which included transcripts that had previously been reported as responsive to stress as well as some functionally unknown transcripts. The ESTs with significant protein homology were sorted into 13 functional categories. A cDNA marcoarray containing the 190 unique ESTs was used to analyze their expression profiles in maize seedling during both PEG treatment and natural drought. The results indicated that 67 ESTs in leaves and 113 ESTs in roots were significantly up-regulated by PEG-stress. 123 ESTs were found to be up-regulated for at least one time-course point in either maize leaves or roots. Correspondingly, 163 ESTs were significantly up-regulated by drought stress. Results from the hierarchical cluster analysis suggest that the leaves and roots of maize seedlings had different expression profiles after PEG treatment and that there was a lot of overlap between PEG- and drought-stress induced up-regulated transcripts. A set of transcripts has been identified, which have significantly increased expression and probably involved in water stress signaling pathway based on data analysis.

Signal peptide of potato PinII enhances the expression of Cry1Ac in transgenic tobacco.

The modified Cry1Ac was expressed in transgenic tobacco plants. To allow secretion of the Cry1Ac protein into the intercellular space, the signal peptide sequence of potato proteinase inhibitor II (pinII) was N-terminally fused to the Cry1Ac encoding region. Expression of Cry1Ac in transgenic tobacco plants was assayed with ELISA. The results showed that pinII signal peptide sequence enhanced the expression of Cry1Ac protein and led to the secretion of the Cry1Ac protein in transgenic tobacco plants. GFP gene was also fused to the signal peptide sequence and transformed to tobacco. The results of fluorescent detection showed that GFP had localized in the apoplast of transgenic plants.