Análise funcional das proteínas HrcA, GroES/GroEL e DnaK/DnaJ em Caulobacter crescentus

O operon groESL de C. crescentus apresenta dupla regulação. A indução deste operon por choque térmico é dependente do fator sigma de choque térmico σ32. A temperaturas fisiológicas, a expressão de groESL apresenta regulação temporal durante o ciclo celular da bactéria e o controle envolve a proteína repressora HrcA e o elemento CIRCE (controlling inverted repeat of chaperonin expression). Para estudar a atividade da proteína repressora in vitro, produzimos e purificamos de E. coli a HrcA de C. creseentus contendo uma cauda de histidinas e a ligação especifica ao elemento CIRCE foi analisada em ensaios de migração retardada em gel de poliacrilamida (EMRGP). A quantidade de DNA retardada pela ligação a HrcA aumentou significativamente na presença de GroES/GroEL, sugerindo que estas proteínas modulam a atividade de HrcA. Corroboração desta modulação foi obtida analisando fusões de transcrição da região regulatória de groESL com o gene lacZ, em células de C. crescentus produzindo diferentes quantidades de GroES/EL. HrcA contendo as substituições Pro81 AJa e Arg87Ala, aminoácidos que se localizam no domínio putativo de ligação ao DNA da proteína, mostraram ser deficientes na ligação a CIRCE, tanto in vitro como in vivo. Em adição, HrcA Ser56Ala expressa na mesma célula juntamente com a proteína selvagem produziu um fenótipo dominante-negativo, indicando que a HrcA de C. crescentus liga-se a CIRCE como um oligômero, provavelmente um dímero. As tentativas de obtenção de mutantes nulos para os genes groESL ou dnaKJ falharam, indicando que as proteínas GroES/GroEL e DnaK/DnaJ são essenciais em C. crescentus, mesmo a temperaturas normais. Foram então construídas no laboratório as linhagens mutantes condicionais SG300 e SG400 de C. crescentus, onde a expressão de groESL e de dnaKJ, respectivamente, está sob controle de um promotor induzido por xilose (PxyIX). Estas linhagens foram caracterizadas quanto á sua morfologia em condições permissivas ou restritivas, assim como quanto à capacidade de sobrevivência frente a vários tipos de estresse. As células da linhagem SG300, exauridas de GroES/GroEL, são resistentes ao choque térmico a 42°C e são capazes de adquirir alguma termotolerância. Entretanto, estas células são sensíveis aos estresses oxidativo, salino e osmótico. As células da linhagem SG400, exauridas de DnaKlJ, são sensíveis ao choque térmico, à exposição a etanol e ao congelamento, e são incapazes de adquirir termotolerância. Além disso, tanto as células exauridas de GroES/GroEL quanto as exauridas de DnaK/DnaJ apresentam problemas na sua morfologia. As células de SG300 exauridas de GroES/GroEL formam filamentos longos que possuem constrições fundas e irregulares. As células de SG400 exauridas de DnaK/DnaJ são apenas um pouco mais alongadas que as células pré-divisionais selvagens e a maioria das células não possuem septo. Estas observações indicam bloqueio da divisão celular, que deve ocorrer em diferentes estágios em cada linhagem.

Urinary Biomarkers Indicative of Apoptosis and Acute Kidney Injury in the Critically Ill.

BACKGROUND Apoptosis is a key mechanism involved in ischemic acute kidney injury (AKI), but its role in septic AKI is controversial. Biomarkers indicative of apoptosis could potentially detect developing AKI prior to its clinical diagnosis. METHODS As a part of the multicenter, observational FINNAKI study, we performed a pilot study among critically ill patients who developed AKI (n = 30) matched to critically ill patients without AKI (n = 30). We explored the urine and plasma levels of cytokeratin-18 neoepitope M30 (CK-18 M30), cell-free DNA, and heat shock protein 70 (HSP70) at intensive care unit (ICU) admission and 24h thereafter, before the clinical diagnosis of AKI defined by the Kidney Disease: Improving Global Outcomes -creatinine and urine output criteria. Furthermore, we performed a validation study in 197 consecutive patients in the FINNAKI cohort and analyzed the urine sample at ICU admission for CK-18 M30 levels. RESULTS In the pilot study, the urine or plasma levels of measured biomarkers at ICU admission, at 24h, or their maximum value did not differ significantly between AKI and non-AKI patients. Among 20 AKI patients without severe sepsis, the urine CK-18 M30 levels were significantly higher at 24h (median 116.0, IQR [32.3-233.0] U/L) than among those 20 patients who did not develop AKI (46.0 [0.0-54.0] U/L), P = 0.020. Neither urine cell-free DNA nor HSP70 levels significantly differed between AKI and non-AKI patients regardless of the presence of severe sepsis. In the validation study, urine CK-18 M30 level at ICU admission was not significantly higher among patients developing AKI compared to non-AKI patients regardless of the presence of severe sepsis or CKD. CONCLUSIONS Our findings do not support that apoptosis detected with CK-18 M30 level would be useful in assessing the development of AKI in the critically ill. Urine HSP or cell-free DNA levels did not differ between AKI and non-AKI patients.

Oxygen sensors and energy sensors act synergistically to achieve a graded alteration in gene expression: Consequences for assessing the level of neuroprotection in response to stressors

Changes in gene expression are associated with switching to an autoprotected phenotype in response to environmental and physiological stress. Ubiquitous molecular chaperones from the heat shock protein (HSP) superfamily confer neuronal protection that can be blocked by antibodies. Recent research has focused on the interactions between the molecular sensors that affect the increased expression of neuroprotective HSPs above constitutive levels. An examination of the conditions under which the expression of heat shock protein 70 (Hsp70) was up regulated in a hypoxia and anoxia tolerant tropical species, the epaulette shark (Hemiscyllium ocellatum), revealed that up-regulation was dependent on exceeding a stimulus threshold for an oxidative stressor. While hypoxic-preconditioning confers neuroprotective changes, there was no increase in the level of Hsp70 indicating that its increased expression was not associated with achieving a neuroprotected state in response to hypoxia in the epaulette shark. Conversely, there was a significant increase in Hsp70 in response to anoxic-preconditioning, highlighting the presence of a stimulus threshold barrier and raising the possibility that, in this species, Hsp70 contributes to the neuroprotective response to extreme crises, such as oxidative stress. Interestingly, there was a synergistic effect of coincident stressors on Hsp70 expression, which was revealed when metabolic stress was superimposed upon oxidative stress. Brain energy charge was significantly lower when adenosine receptor blockade, provided by treatment with aminophylline, was present prior to the final anoxic episode, under these circumstances, the level of Hsp70 induced was significantly higher than in the pair-matched saline treated controls. An understanding of the molecular and metabolic basis for neuroprotective switches, which result in an up-regulation of neuroprotective Hsp70 expression in the brain, is needed so that intervention strategies can be devised to manage CNS pathologies and minimise damage caused by ischemia and trauma. In addition, the current findings indicate that measurements of HSP expression per se may provide a useful correlate of the level of neuroprotection achieved in the switch to an autoprotected phenotype.

Global changes in gene expression observed at the transition from growth to stationary phase in Listeria monocytogenes ScottA batch culture

Listeria monocytogenes is a food-borne Gram-positive bacterium that is responsible for a variety of infections (worldwide) annually. The organism is able to survive a variety of environmental conditions and stresses, however, the mechanisms by which L. monocytogenes adapts to environmental change are yet to be fully elucidated. An understanding of the mechanism(s) by which L. monocytogenes survives unfavourable environmental conditions will aid in developing new food processing methods to control the organism in foodstuffs. We have utilized a proteomic approach to investigate the response of L. monocytogenes batch cultures to the transition from exponential to stationary growth phase. Proteomic analysis showed that batch cultures of L. monocytogenes perceived stress and began preparations for stationary phase much earlier (approximately A(600) = 0.75, mid-exponential) than predicted by growth characteristics alone. Global analysis of the proteome revealed that the expression levels of more than 50% of all proteins observed changed significantly over a 7-9 h period during this transition phase. We have highlighted ten proteins in particular whose expression levels appear to be important in the early onset of the stationary phase. The significance of these findings in terms of functionality and the mechanistic picture are discussed.

Plasma cytokine changes in relation to exercise intensity and muscle damage

The purpose of this study was to compare the effects of exercise intensity and exercise-induced muscle damage on changes in anti-inflammatory cytokines and other inflammatory mediators. Nine well-trained male runners completed three different exercise trials on separate occasions: ( 1) level treadmill running at 60% VO2max (moderate-intensity trial) for 60 min; (2) level treadmill running at 85% VO2max (high-intensity trial) for 60 min; (3) downhill treadmill running ( - 10% gradient) at 60% VO2 max (downhill running trial) for 45 min. Blood was sampled before, immediately after and 1 h after exercise. Plasma was analyzed for interleukin-1 receptor antagonist (IL-1ra), IL-4, IL-5, IL-10, IL-12p40, IL-13, monocyte chemotactic protein-1 (MCP-1), prostaglandin E-2, leukotriene B-4 and heat shock protein 70 (HSP70). The plasma concentrations of IL-1ra, IL-12p40, MCP-1 and HSP70 increased significantly (P< 0.05) after all three trials. Plasma prostaglandin E-2 concentration increased significantly after the downhill running and high-intensity trials, while plasma IL-10 concentration increased significantly only after the high-intensity trial. IL-4 and leukotriene B4 did not increase significantly after exercise. Plasma IL-1ra and IL-10 concentrations were significantly higher ( P< 0.05) after the high-intensity trial than after both the moderate-intensity and downhill running trials. Therefore, following exercise up to 1 h duration, exercise intensity appears to have a greater effect on anti-inflammatory cytokine production than exercise-induced muscle damage.

PerR controls Mn-dependent resistance to oxidative stress in Neisseria gonorrhoeae

In previous studies it has been established that resistance to superoxide by Neisseria gonorrhoeae is dependent on the accumulation of Mn(II) ions involving the ABC transporter, MntABC. A mutant strain lacking the periplasmic binding protein component (MntC) of this transport system is hypersensitive to killing by superoxide anion. In this study the mntC mutant was found to be more sensitive to H2O2 killing than the wild-type. Analysis of regulation of MntC expression revealed that it was de-repressed under low Mn(II) conditions. The N. gonorrhoeae mntABC locus lacks the mntR repressor typically found associated with this locus in other organisms. A search for a candidate regulator of mntABC expression revealed a homologue of PerR, a Mn-dependent peroxide-responsive regulator found in Gram-positive organisms. A perR mutant expressed more MntC protein than wild-type, and expression was independent of Mn(II), consistent with a role for PerR as a repressor of mntABC expression. The PerR regulon of N. gonorrhoeae was defined by microarray analysis and includes ribosomal proteins, TonB-dependent receptors and an alcohol dehydrogenase. Both the mntC and perR mutants had reduced intracellular survival in a human cervical epithelial cell model.

The effectiveness of heat, cold and 6-dimethylaminopurine shocks for inducing tetraploidy in the Kuruma shrimp, Marsupenaeus japonicus (Bate)

In this study tetraploid Marsupenaeus japonicus (Bate) embryos were produced by preventing the first division in mitosis. The effectiveness of temperature and chemical shocks for producing tetraploid M. japonicus were assessed when applied at different times postspawning and for different durations. Tetraploid M. japonicus embryos (spawned at 27 degrees C) were produced by heat shocks at 35 degrees C and 36 degrees C in three and eight spawning samples respectively, and a cold shock at 5 degrees C in a single spawning sample. All temperature shocks inducing tetraploidy were applied 18-23 min postspawning for a 5-10 min duration. The percentage of spawnings successfully inducing tetraploid embryos (i.e., frequency of induction) ranged from 33.33% to 66.67% for the 21, 22 and 23 min postspawning heat shock treatment regimes. The percentage of tetraploid embryos within an induction (i.e., induction rate), as determined by flow cytometry, ranged from 8.82% to 98.12% (ave. S.E.) (34.4 +/- 21.4%) for the 35 degrees C shock treatments, from 13.12% to 61.02% (35.0 +/- 5.0%) for the 36 degrees C shock treatments and was 15% for the 5 degrees C cold shock treatment. No tetraploids were produced for spawnings that received heat shocks above 36 degrees C or below 35 degrees C, or for cold shocks above 5 degrees C for any of the tested postspawning treatment and duration times. Chemical shock with 150 mu M 6-dimethylaminopurine did not result in tetraploid M. japonicus embryos at any of the tested postspawning treatment times and durations. Tetraploid M. japonicus embryos were nonviable, with no tetraploid larvae being detected by flow cytometry. Based on our results heat shocking of M. japonicus embryos at 36 degrees C, 23 min postspawning for a 5-10 min duration is the most effective means to produce tetraploids through inhibition of the first mitotic division (taking into consideration the importance of frequency and induction rate equally).

Mechanisms of Mycoplasma-induced inflammation and cellular transformation

There is a growing interest in “medical gasses” for their antibacterial and anti-inflammatory properties. Hydrogen sulfide (H2S), a member of the family of gasotransmitters, is in fact increasingly being recognized as an important signaling molecule, but its precise role in the regulation of the inflammatory response is still not clear. For this reason, the aim of the first part of this thesis was to investigate the effects of H2S on the expression of pro-inflammatory cytokines, such as MCP-1, by using an in vitro model composed by both primary monocytes-derived macrophages cultures and the human monocytic cell line U937 infected with Mycoplasma fermentans, a well-known pro-inflammatory agent. In our experiments, we observed a marked increase in the production of pro-inflammatory cytokines in infected cells. In particular, MCP-1 was induced both at the RNA and at the protein level. To test the effects of H2S on infected cells, we treated the cells with two different H2S donors (NaHS and GYY4137), showing that both H2S treatments had anti-inflammatory effects in Mycoplasma-infected cells: the levels of MCP-1, both mRNA expression and protein production, were reduced. Our subsequent studies aimed at understanding the molecular mechanisms responsible for these effects, focused on two specific molecular pathways, both involved in inflammation: the NF-κB and the Nrf2 pathway. After treatment with pharmacological inhibitors, we demonstrated that Mycoplasma fermentans induces MCP-1 expression through the TLR-NF-κB pathway with the nuclear translocation of its subunits, while treatment with H2S completely blocked the nuclear translocation of NF-κB heterodimer p65/p50. Then, once infected cells were treated with H2S donors, we observed an increased protective effect of Nrf2 and also a decrease in ROS production. These results highlight the importance of H2S in reducing the inflammatory process caused by Mycoplasma fermentans. To this regard, it should be noted that several projects are currently ongoing to develop H2S-releasing compounds as candidate drugs capable of alleviating cell deterioration and to reduce the rate of decline in organ function. In the second part of this study, we investigated the role of Mycoplasma infection in cellular transformation. Infectious agents are involved in the etiology of many different cancers and a number of studies are still investigating the role of microbiota in tumor development. Mycoplasma has been associated with some human cancers, such as prostate cancer and non-Hodgkin’s lymphoma in HIV-seropositive people, and its potential causative role and molecular mechanisms involved are being actively investigated. To this regard, in vitro studies demonstrated that, upon infection, Mycoplasma suppresses the transcriptional activity of p53, key protein in the cancer suppression. As a consequence, infected cells were less susceptible to apoptosis and proliferated more than the uninfected cells. The mechanism(s) responsible for the Mycoplasma-induced inhibitory effect on p53 were not determined. Aim of the second part of this thesis was to better understand the tumorigenic role of the microorganism, by investigating more in details the effect(s) of Mycoplasma on p53 activity in an adenocarcinoma HCT116 cell line. Treatment of Mycoplasma-infected cells with 5FU or with Nutlin, two molecules that induce p53 activity, resulted in cellular proliferation comparable to untreated controls. These results suggested that Mycoplasma infection inhibited p53 activity. Immunoprecipitation of p53 with specific antibodies, and subsequent Gas Chromatography and Mass Spectroscopy (GC-MS) assays, allowed us to identify several Mycoplasma-specific proteins interacting with p53, such as DnaK, a prokaryotic heat shock protein and stress inducible chaperones. In cells transfected with DnaK we observed i) reduced p53 protein levels; ii) reduced activity and expression of p21, Bax and PUMA, iii) a marked increase in cells leaving G1 phase. Taken together, these data show an interaction between the human p53 and the Mycoplasma protein DnaK, with the consequent decreased p53 activity and decreased capability to respond to DNA damage and prevent cell proliferation. Our data indicate that Mycoplasma could be involved in cancer formation and the mechanism(s) has the potential to be a target for cancer diagnosis and treatment(s).

Seawater carbonate chemistry and echinoderm Asterias rubens biological processes during experiments, 2011

We compared effects of exposure to predicted near-future (2100) ocean acidification (OA; pH 7.7) and normal seawater (Control; pH 8.1) on immune and stress responses in the adult sea star Asterias rubens. Analyses were made after one week and after six months of continuous exposure. Following one week exposure to acidified water, the pH of coelomic fluid was significantly reduced. Levels of the chaperon Hsp70 were elevated while key cellular players in immunity, coelomocytes, were reduced by approximately 50%. Following long-term exposure (six months) levels of Hsp70 returned to control values, whereas immunity was further impaired, evidenced by the reduced phagocytic capacity of coelomocytes and inhibited activation of p38 MAP-kinase. Such impacts of reduced seawater pH may have serious consequences for resistance to pathogens in a future acidified ocean.

Repeated evolution of heat responsiveness among Brassicaceae COPIA transposable elements

Eukaryotic genomes contain repetitive DNA sequences. This includes simple repeats and more complex transposable elements (TEs). Many TEs reach high copy numbers in the host genome, owing to their amplification abilities by specific mechanisms. There is growing evidence that TEs contribute to gene transcriptional regulation. However, excess of TE activity may lead to reduced genome stability. Therefore, TEs are suppressed by the transcriptional gene silencing machinery via specific chromatin modifications. In contrary, effectiveness of the epigenetic silencing mechanisms imposes risk for TE survival in the host genome. Therefore, TEs may have evolved specific strategies for bypassing epigenetic control and allowing the emergence of new TE copies. Recent studies suggested that the epigenetic silencing can be, at least transiently, attenuated by heat stress in A. thaliana. Heat stress induced strong transcriptional activation of COPIA78 family LTR-retrotransposons named ONSEN, and even their transposition in mutants deficient in siRNA-biogenesis. ONSEN transcriptional activation was facilitated by the presence of heat responsive elements (HREs) within the long terminal repeats, which serve as a binding platform for the HEAT SHOCK FACTORs (HSFs). This thesis focused on the evolution of ONSEN heat responsiveness in Brassicaceae. By using whole-transcriptome sequencing approach, multiple Arabidopsis lyrata ONSENs with conserved heat response were found and together with ONSENs from other Brassicaceae were used to reconstruct the evolution of ONSEN HREs. This indicated ancestral situation with two, in palindrome organized, HSF binding motifs. In the genera Arabidopsis and Ballantinia, a local duplication of this locus increased number of HSF binding motifs to four, forming a high-efficiency HRE. In addition, whole transcriptome analysis revealed novel heat-responsive TE families COPIA20, COPIA37 and HATE. Notably, HATE represents so far unknown COPIA family which occurs in several Brassicaceae species but is absent in A. thaliana. Putative HREs were identified within the LTRs of COPIA20, COPIA37 and HATE of A. lyrata, and could be preliminarily validated by transcriptional analysis upon heat induction in subsequent survey of Brassicaeae species. Subsequent phylogenetic analysis indicated a repeated evolution of heat responsiveness within Brassicaceae COPIA LTR-retrotransposons. This indicates that acquisition of heat responsiveness may represent a successful strategy for survival of TEs within the host genome.

Characterization of heat waves affecting mortality rates of broilers between 29 days and market age

Climate may affect broiler production, especially where there are heat waves, which may cause high mortality rates due to the heat stress. Heat wave prediction and characterization may allow early mitigation actions to be taken. Data Mining is one of the tools used for such a characterization, particularly when a large number of variables is involved. The objective of this study was to classify heat waves that promote broiler chicken mortality in poultry houses equipped with minimal environmental control. A single day of heat, a heat-shock day, is capable of producing high broiler mortality. In poultry houses equipped with fans and evaporative cooling, the characterization of heat waves affecting broiler mortality between 29 days of age and market age presented 89.34% Model Accuracy and 0.73 Class Precision for high mortality. There was no influence on high mortality (HM) of birds between 29 and 31 days of age. Maximum temperature humidity index (THI) above 30.6 ºC was the main characteristic of days when there was a heat wave, causing high mortality in broilers older than 31 days. The high mortality of broilers between 31 and 40 days of age occurred when maximum THI was above 30.6 ºC and maximum temperature of the day was above 34.4 ºC. There were two main causes of high mortality of broilers older than 40 days: 1) maximum THI above 30.6 ºC and minimum THI equal or lower than 15.5 ºC; 2) maximum THI above 30.6 ºC, minimum THI lower than 15.5 ºC, and the time of maximum temperature later than 15:00h. The heat wave influence on broiler mortality lasted an average of 2.7 days.

Helminth Coinfection Does Not Affect Therapeutic Effect of a DNA Vaccine in Mice Harboring Tuberculosis

Background: Helminthiasis and tuberculosis (TB) coincide geographically and there is much interest in exploring how concurrent worm infections might alter immune responses against bacilli and might necessitate altered therapeutic approaches. A DNA vaccine that codifies heat shock protein Hsp65 from M. leprae (DNAhsp65) has been used in therapy during experimental tuberculosis. This study focused on the impact of the co-existence of worms and TB on the therapeutic effects of DNAhsp65. Methodology/Principal Findings: Mice were infected with Toxocara canis or with Schistosoma mansoni, followed by coinfection with M. tuberculosis and treatment with DNAhsp65. While T. canis infection did not increase vulnerability to pulmonary TB, S. mansoni enhanced susceptibility to TB as shown by higher numbers of bacteria in the lungs and spleen, which was associated with an increase in Th2 and regulatory cytokines. However, in coinfected mice, the therapeutic effect of DNAhsp65 was not abrogated, as indicated by colony forming units and analysis of histopathological changes. In vitro studies indicated that Hsp65-specific IFN-gamma production was correlated with vaccine-induced protection in coinfected mice. Moreover, in S. mansoni-coinfected mice, DNA treatment inhibited in vivo TGF-beta and IL-10 production, which could be associated with long-term protection. Conclusions/Significance: We have demonstrated that the therapeutic effects of DNAhsp65 in experimental TB infection are persistent in the presence of an unrelated Th2 immune response induced by helminth infections.

A reliable measure of similarity based on dependency for short time series: an application to gene expression networks

Background: Microarray techniques have become an important tool to the investigation of genetic relationships and the assignment of different phenotypes. Since microarrays are still very expensive, most of the experiments are performed with small samples. This paper introduces a method to quantify dependency between data series composed of few sample points. The method is used to construct gene co-expression subnetworks of highly significant edges. Results: The results shown here are for an adapted subset of a Saccharomyces cerevisiae gene expression data set with low temporal resolution and poor statistics. The method reveals common transcription factors with a high confidence level and allows the construction of subnetworks with high biological relevance that reveals characteristic features of the processes driving the organism adaptations to specific environmental conditions. Conclusion: Our method allows a reliable and sophisticated analysis of microarray data even under severe constraints. The utilization of systems biology improves the biologists ability to elucidate the mechanisms underlying celular processes and to formulate new hypotheses.

Induction of Heme Oxygenase-1 Can Halt and Even Reverse Renal Tubule-Interstitial Fibrosis

Background: The tubule-interstitial fibrosis is the hallmark of progressive renal disease and is strongly associated with inflammation of this compartment. Heme-oxygenase-1 (HO-1) is a cytoprotective molecule that has been shown to be beneficial in various models of renal injury. However, the role of HO-1 in reversing an established renal scar has not yet been addressed. Aim: We explored the ability of HO-1 to halt and reverse the establishment of fibrosis in an experimental model of chronic renal disease. Methods: Sprague-Dawley male rats were subjected to unilateral ureteral obstruction (UUO) and divided into two groups: non-treated and Hemin-treated. To study the prevention of fibrosis, animals were pre-treated with Hemin at days -2 and -1 prior to UUO. To investigate whether HO-1 could reverse established fibrosis, Hemin therapy was given at days 6 and 7 post-surgery. After 7 and/or 14 days, animals were sacrificed and blood, urine and kidney tissue samples were collected for analyses. Renal function was determined by assessing the serum creatinine, inulin clearance, proteinuria/creatininuria ratio and extent of albuminuria. Arterial blood pressure was measured and fibrosis was quantified by Picrosirius staining. Gene and protein expression of pro-inflammatory and pro-fibrotic molecules, as well as HO-1 were performed. Results: Pre-treatment with Hemin upregulated HO-1 expression and significantly reduced proteinuria, albuminuria, inflammation and pro-fibrotic protein and gene expressions in animals subjected to UUO. Interestingly, the delayed treatment with Hemin was also able to reduce renal dysfunction and to decrease the expression of pro-inflammatory molecules, all in association with significantly reduced levels of fibrosis-related molecules and collagen deposition. Finally, TGF-beta protein production was significantly lower in Hemin-treated animals. Conclusion: Treatment with Hemin was able both to prevent the progression of fibrosis and to reverse an established renal scar. Modulation of inflammation appears to be the major mechanism behind HO-1 cytoprotection.

Drying and storage of cauliflower (Brassica oleracea var. botrytis) hydroprimed seeds

Literature has documented beneficial effects of seed priming on speed, synchronization and uniformity of germination. often leading to improved stand establishment. However. doubts still persist about the possible reversal effects, after drying and during storage of primed seeds that could overcome, partial or totally, the improved performance. The objectives of this research were to identify drying and storage procedures that would maintain the physiological performance achieved after seed priming, without negative effects on storability. First. hydroprimed cauliflower Seeds cv. Sharon and cv. Teresopolis Gigante, each represented by three seed lots were submitted to fast drying, slow drying, and treatments of pre-drying incubation (exposure to 35 degrees C, to a polyethylene glycol 6000 solution or a heat shock) followed by fast drying. In the second phase of this study, hydroprimed seed samples were submitted to fast drying (30-35 degrees C and 40-50% R.H.) and stored under laboratory conditions or in a chamber at 20 degrees C and 50% relative humidity for six months. Seed physiological potential was evaluated after 60-day intervals for germination (speed and percentage), Seedling emergence and saturated salt accelerated aging tests. All drying treatments efficiently preserved the favourable priming effects, except for the incubation at 35 degrees C for 96-144 hours. The beneficial priming effects followed by fast drying persisted for four months under controlled conditions (20 degrees C and 50% relative humidity).