Defense involvement of piscidin from striped murrel Channa striatus and its peptides CsRG12 and CsLC11 involvement in an antimicrobial and antibiofilm activity

In this study, we have evaluated bioinformatics characterization and antimicrobial role of two piscidin (Pi) peptide identified from the established transcriptome of striped murrel Channa striatus (Cs). The identified CsPi cDNA contains 256 nucleotides encode a protein with 70 amino acids in length which has two antimicrobial peptides and named CsRG12 and CsLC11. The gene expression analysis with various immune stimulants indicated an induced expression pattern of CsPi. Antibiogram showed that CsRG12 and CsLC11 was active against Staphylococcus aureus ATCC 33592, a major multi-drug resistant (MDR) bacterial pathogen and Bacillus cereus ATCC 2106. The minimum inhibitory concentration (MIC) and antibiofilm assays were conducted to observe the activity of pathogenic bacteria with these derived antimicrobial peptides. Flow cytometry analysis noticed that the CsRG12 and CsLC11 disrupt the membrane formation of S. aureus and B. cereus, which was further assured by scanning electron microscopic (SEM) images that bleb formation leads to disruption around the bacterial membrane. Overall, it is reported that CsPi is involved in innate immunity as the gene expression plays a remarkable role in up and down regulation during infection. In addition, the involvement of peptides in antibiofilm formation and bacterial membrane disruption support its immune character. This study leads to a possibility for the development of therapeutics in aquaculture biotechnology.

Antibacterial activity of some folklore medicinal plants from South India

Antibacterial activity and phytochemical tests of eight whole plant methanol extracts belonging to family Euphorbiaceae were evaluated. In agar well diffusion assay the diameter of inhibition zones ranged from 3-13 mm. Phyllanthus emblica showed maximum activity of 13 mm. The MIC and MBC observed were 30-140 mcg/ml and 40-160 mcg/ml, respectively. P. piscatorum and P. emblica showed the lowest MIC (30 mcg/ml), P. emblica the lowest MBC (40 mcg/ml) and thus an effective inhibitor of the tested bacteria. Alkaloids, saponins and tannins were detected in 7 out of 8 tested plants.

Double MITs and magnetoresistance: an intrinsic feature of Ru substituted La(0.67)Ca(0.33)MnO(3)

In this paper, we examine the possible influence of extrinsic factors on the electrical and magnetotransport of La(0.67)Ca(0.33)Mn(1-x)Ru(x)O(3) (x≤0.10). Ru substitution results in double metal-insulator transitions (MITs) at T(MI1) and T(MI2), both exhibiting magnetoresistance (MR). No additional magnetic signal corresponding to a second low-temperature maximum (LTM) at T(MI2) could be observed, either in ac susceptibility (χ(')) or in specific heat (C(p)). Typical grain sizes of ∼18 000-20 000 nm, as estimated from the scanning electron microscope (SEM) micrographs, are not so small as to warrant an LTM. The absence of additional peaks in the high statistics powder x-ray diffraction (XRD), a linear systematic increase of the unit cell parameters, close matching of the transition temperatures in resistivity, χ(') and C(p) and their linear systematic decrease with x, and an homogeneous distribution of Mn, Ru and O at arbitrarily selected regions within and across the grains exclude chemical inhomogeneity in the samples. The insensitivity of grain boundary MR at 5 K to Ru composition indicates that the grain boundary is not altered to result in an LTM. Oxygen stoichiometry of all the compounds is close to the nominal value of 3. These results not only exclude the extrinsic factors, but also establish that double MITs, both exhibiting MR, are intrinsic to Ru substituted La(0.67)Ca(0.33)MnO(3).

Spin trap (N-t-butyl-alpha-phenylnitrone)-mediated suprainduction of heme oxygenase-1 in kidney ischemia/reperfusion model: role of the oxygenase in protection against oxidative injury

In mammals the rate-limiting step in heme catabolism is the heme oxygenase (HO) system. Two isozymes, HO-1 and HO-2, oxidatively cleave the substrate to form biliverdin, and the potential cellular messenger, CO; the chelated iron is released as the result of the tetrapyrrole ring opening. Biliverdin is subsequently reduced to bilirubin, an antioxidant, by biliverdin reductase. The aim of the present study was to investigate the involvement of HO-1, a heat shock/stress protein, in protection offered by the spin trap agent, N-tert-butyl-alpha-phenyl-nitrone (PBN), against kidney ischemia/reperfusion injury. For this, HO-1 expression and assessment of the parameters associated with tissue-oxidative injury were compared in the presence or absence of PBN pretreatment of rats (100 mg/kg i.p., 30 min) before the onset of 30-min ischemia. Twenty-four hours after reperfusion, Northern blot analysis showed an unprecedented approximately 37-fold increase in 1.8-kb HO-1 mRNA in PBN pretreated rat kidney; HO-2 mRNA levels did not increase. At 48 h, the levels of HO-1 mRNA remained nearly 14-fold higher than the control value. In the absence of PBN, the levels measured approximately 5- and 2-fold higher than control values at the 24- and 48-h intervals, respectively. PBN pretreatment also resulted in a most impressive increase in the levels of HO-1 protein as judged by Western blot analysis and measurement of enzyme activity at the 24-h time point. As detected by immunohistochemical analysis, PBN pretreatment caused an increase in HO-1 and biliverdin reductase-immunoreactive proteins in the cortex and in the outer stripe of the outer medulla. In the absence of PBN pretreatment, there was an intense immunostaining for HO-1 in the medullary rays, which corresponded with iron and lipid peroxidation staining of the region; these observations were not made with PBN-pretreated kidneys. Collectively, the findings are consistent with the likelihood that suprainduction of HO-1 gene expression protects the kidney from free radical-mediated injury by increasing the capacity to produce the potent cellular antioxidant bilirubin. We also suggest spin trap-mediated protection against ischemia/reperfusion injury is likely due to a sustained elevation of HO-1 gene expression by formation of stable radicals.

Chamber-specific regulation of heme oxygenase-1 (heat shock protein 32) in right-sided congestive heart failure

Heme oxygenase (HO)-1 is a stress protein (HSP 32) and, together with HO-2, catalyses oxidation of the heme molecule to generate carbon monoxide, a gas with vasodilatory properties, and bilirubin, an antioxidant. Right-sided heart failure (RHF) resulted in a two-fold increase in the HO-1 transcript (;1.8 kb) in the right ventricle (RV) of RHF dogs compared to that of controls. In contrast, the left ventricle showed no increase in HO-1 mRNA in RHF. The change in HO was unique to HO-1, because neither the HO-2 transcripts (;1.3 and 1.9 kb) nor the HSP 70 mRNA was altered in either ventricle. This increase in HO-1 mRNA in RV was accompanied by a two-fold increase in immunoreactive HO-1 protein, as judged by Western blot analysis, as well as by a significant increase in cGMP levels. There was, however, no significant increase in RV total nitric oxide synthase activity in RHF. Furthermore, since norepinephrine infusion also increased HO-1 transcript and protein levels, the HO-1 system probably was induced in RHF by the increased interstitial norepinephrine levels known to occur in failing myocardium. This differential regulation and induction of HO-1 gene in the failing ventricle might be one of the defense mechanisms by which the heart attempts to protect from stress caused by congestive heart failure.

Altered sarcoplasmic reticulum Ca2+ ATPase gene expression in congestive heart failure: effect of chronic norepinephrine infusion

We have examined the ryanodine receptor, Ca(2+)-ATPase, calsequestrin and phospholamban mRNA levels in the left ventricles of pacing-induced heart failure and norepinephrine infusion dogs. The heart failure dogs showed a decrease in the levels of ryanodine receptor and Ca(2+)-ATPase mRNAs. Norepinephrine infusion caused a reduction of Ca(2+)-ATPase mRNA but no change in ryanodine receptor mRNA. There was a corresponding reduction of the immunoreactive Ca(2+)-ATPase protein levels in both heart failure and norepinephrine infusion animals compared to controls. In contrast, the mRNAs of calsequestrin and phospholamban were unchanged in dogs with either congestive heart failure or norepinephrine infusion. Thus, since norepinephrine infusion and congestive heart failure produced similar reductions of Ca(2+)-ATPase mRNA and protein, we postulate that the down-regulation of Ca(2+)-ATPase in congestive heart failure may be caused, at least in part, by sympathetic stimulation that occurs in heart failure.

Regulation of heme oxygenase-2 by glucocorticoids in neonatal rat brain: characterization of a functional glucocorticoid response element

Heme oxygenase-2 (HO-2) is constitutively expressed in mammalian tissues; together with HO-1 (HSP32) it catalyzes the cleavage of heme to produce biliverdin IX alpha, CO and Fe. Detection of a consensus sequence of the glucocorticoid response element (GRE) in the promoter region of the HO-2 gene prompted the present study which has investigated the role of glucocorticoids (Gcs) in the regulation of HO-2 protein and transcript development in the newborn rat brain and has examined the promoter activity of the GRE in HeLa cells. Using in situ hybridization histochemistry, we noted a pronounced increase in signal for HO-2 mRNA in the brain of 14-day-old rats postnatally treated with corticosterone (5 microg/g, 4 x, starting 24-36 h after birth). And, using immunohistochemistry, a striking increase in neuronal HO-2 immunostaining in treated brains was detected. The HO-2 GRE was tested for responsiveness to dexamethasone (DX) using both a promoterless CAT expression vector, and a heterologous promoter containing luciferase expression vector in HeLa cells. The HO-2 promoter containing the GRE and transcription start site induced CAT reporter gene activity in response to DX, whereas mutation or deletion in the GRE abolished hormone responsiveness. Similarly, constructs containing the GRE conferred responsiveness to DX in an orientation-independent manner and increased relative luciferase activity. Further, specific binding of glucocorticoid receptor protein to the GRE was observed; binding could be competed out only by excess cold GRE and not by mutated HO-2 GRE, or AP1. HO-2 mRNAs (approximately 1.3 and approximately 1.9 kb) increased in HeLa cells treated with DX (5 microM), the level reached a maximum at 24 h. DX did not effect HO-1 mRNA level. The increase in the HO-2 transcript was accompanied by an increase in HO-2 protein, as assessed by Western blot analysis, and an increase in HO activity, as measured by bilirubin formation. Also, an increase in intensity of immunostaining was noted in DX-treated HeLa cells. We conclude that the GRE present in the HO-2 gene promoter region is functional, and propose the direct involvement of the adrenal glucocorticoids in modulation of HO-2 gene expression. In the context of biological functions of heme degradation products, we suggest that this regulation may be of significance, particularly to the neurons.

Renal ischemia/reperfusion up-regulates heme oxygenase-1 (HSP32) expression and increases cGMP in rat heart

For the first time, the authors report an intimate link between kidney and heart functions as it pertains to the regulation of stress protein gene expression in the heart. They show that the stress on the target organ, the kidney, is translated into a response in the cardiovascular system, as reflected by the induction of heme oxygenase (HO)-1 gene expression, which, in turn, may be a cellular defense response as suggested by an increase in cGMP level in the heart, and an increase in the rate of bilirubin formation by the kidney and the heart. HO-1 is a stress protein (HSP32) and, together with HO-2, catalyzes oxidation of the heme molecule to generate CO, a likely signal molecule for the generation of cGMP, and bilirubin, an antioxidant. Specifically, bilateral renal ischemia for 30 min caused a 3-fold increase in the approximately 1.8-kb HO-1 mRNA in the heart within 4 h after reperfusion and remained essentially at this level for 24 h, at which point, a 2.6-fold increase in HO-1 mRNA in the descending aorta was also detected. Heart HO-1 mRNA remained elevated for more than 48 h; in contrast, at the 48-h time point, the transcript level in the kidney, which had increased by 10-fold 24 h after reperfusion, had returned to the control level. Neither in the heart nor in the kidney did HO-2 transcripts (approximately 1.3 and 1.9 kb) respond to renal ischemia/ reperfusion. The increase in heart HO-1 transcript level was accompanied by an increase in HO-1 protein, as judged by Western blot and immunohistochemical analysis, and in enzyme activity, as judged by bilirubin formation. In addition, cGMP concentration in the heart was elevated when measured at 24 h and 48 h after reperfusion of the kidney, in the absence of an increase in the activity of NO. Data suggest that hemodynamic stress caused by the occlusion of the renal artery is responsible for activation of HO-1 gene expression in the heart. An argument is made for the role of HO-1 in the defense mechanisms of the heart pertaining to the enzyme's function in a hemoprotein regulatory capacity, along with the biological activity of its products.

Cranial sonography in pyogenic meningitis in neonates and infants

Cranial sonography was performed in 34 infants with proven meningitis and with clinical suspicion of its complications, utilizing the patent anterior fontanelle. Twenty-five patients showed various sonographic findings which included ventriculomegaly, echogenic sulci, subdural effusion, ventriculitis, infarction/cerebritis, cerebral oedema, porencephalic cyst, etc. Sonography is safe and cost-effective in diagnosis of complications, and management of pyogenic meningitis in infants.

Induction of heart heme oxygenase-1 (HSP32) by hyperthermia: possible role in stress-mediated elevation of cyclic 3':5'-guanosine monophosphate

Presently we have investigated the carbon monoxide generating capacity of the cardiovascular system under normal and stress conditions by examining the microsomal heme oxygenase system at the transcript, protein and activity levels; and have assessed response of heart nitric oxide (NO) synthase activity and cyclic GMP levels to stress. Heme oxygenase (HO) isozymes, HO-1 (HSP32) and HO-2, catalyze the rate limiting step in the only known pathway in eukaryotes for the generation of the potential cellular message, carbon monoxide, and the antioxidant, bilirubin. We show expression of HO-1 and HO-2 at both the transcription and protein levels under normal conditions in the heart and descending aorta, and demonstrate the sensitivity of only the HO-1 isozyme to heat stress in these tissues. The ratio of the two HO-2 homologous transcripts (approximately 1.9 and 1.3 Kb) present in the atrium, ventricles and descending aorta and their levels were not altered by hyperthermia (42 degrees C, 20 min) when measured 1 or 6 hr after treatment. In contrast, hyperthermia caused a rapid, robust and coordinate increase of approximately 10- to 32-fold in the approximately 1.8-Kb HO-1 mRNA in these tissues when measured 1-hr post-treatment. Hyperthermia also caused a significant increase in both HO-1 protein and heme degradation capacity in the heart. Furthermore, the induction of HO-1 protein in the heart was accompanied by a significant elevation in tissue cyclic GMP level first detected 1-hr post-treatment and was sustained 6 hr after heat shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Coordinated expression and mechanism of induction of HSP32 (heme oxygenase-1) mRNA by hyperthermia in rat organs

Heme oxygenase isozymes, HO-1 and HO-2, catalyze the cleavage of heme b (Fe-protoporphyrin-IX) at the alpha-meso carbon bridge to form the antioxidant, biliverdin IX alpha, and the putative cellular messenger, carbon monoxide. HO-1 is a heat shock (HSP32) or stress protein, while HO-2 is a noninducible enzyme. Presently, we have examined the time course of expression of HSP32 in liver, kidney, and heart of rats exposed to hyperthermia and investigated the mechanism of induction of HO-1 by hyperthermia. We report a coordinated induction response of all organs to elevated ambient temperature (42 degrees C, 20 min). Specifically, the maximum induction of the 1.8 kb HO-1 mRNA was observed 1 h after hyperthermia and reached a value 20-40-fold that of the control; the transcript level approximated the control value by 6 h after heat stress. In contrast, the levels and the ratio of the 1.3 and 1.9 kb HO-2 transcripts were not affected by hyperthermia. As judged by in vitro nuclear transcription run-on assays, thermal stress caused the stimulation of HO-1 gene transcription. The increase in HO-1 mRNA transcription was accompanied by an increase in binding of nuclear factor(s) to the heat shock element in the promoter region of the gene. The increase of the HO-1 mRNA was reflected in increases in both heme oxygenase activity and in immunoreactive HO-1 protein. We suggest that the induction of heme oxygenase by heat stress is a physiologically relevant defense mechanism whereby both the degradation of heme of denatured hemoproteins and the generation of biologically active products of heme catabolism are enhanced.

Steroids and their conjugates in the mammalian brain

Five steroids--3 beta-hydroxypregn-5-en-20-one (pregnenolone; P), 3 beta-hydroxy-5 alpha-pregnan-20-one (3 beta-AP), 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-AP), 3 beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone; D), and 3 beta-hydroxy-5 alpha-androstan-17-one (EpiA)--were extracted from the brains of adult male rats, rabbits, and dogs. The steroids exist in this organ as unconjugated compounds and as sulfates, lipoidal esters, and sulfolipids. The techniques for separating these four classes of steroids from each other and for separating the five steroids from each other are described. In all cases, the steroids were identified by their retention time (Rt) on HPLC, their Rt by gas chromatography, and by selected ion monitoring of their mass spectra. The latter were also used for quantification. In their reaction toward organic bases, the sulfolipid conjugates resemble previously described sulfolipids of cholesterol and sitosterol. These conjugates are relatively abundant in brain, particularly those of P and D, and this suggests that, in the search for the physiological significance of these brain constituents, these conjugates warrant attention.

Anti-poly(A) polymerase antibodies in the sera of tumor-bearing rats can inhibit specific cleavage and polyadenylation reactions

Sera from rats bearing Morris hepatoma 3924A for 7 weeks contained antibodies against the 48 kd tumor-type poly(A) polymerase, whereas sera from normal rats or rats bearing the tumor for shorter periods did not exhibit immunoreactivity against the enzyme. Purified IgG from the sera of the tumor-bearing rats inhibited both cleavage at the poly(A) site and polyadenylation of adenovirus L3 RNA in nuclear extracts derived from HeLa cells. By contrast, IgG from normal rats did not block the 3'-terminal processing reaction. Control or immune IgG had no effect on the transcription of ribosomal gene in the extracts derived from H-4 hepatoma cells. These data demonstrate the functional specificity of the anti-poly(A) polymerase antibodies found in the sera of the tumor-bearing rats.

Association of poly(A) polymerase with U1 RNA

Previous studies (Stetler, D. A., and Jacob, S. T. (1984) J. Biol. Chem. 259, 7239-7244) have shown that poly(A) polymerase from adult rat liver (liver-type) is structurally and immunologically distinct from the corresponding rat hepatoma (tumor-type) enzyme. When hepatoma 7777 (McA-RH 7777) cells were labeled with [32P]inorganic phosphate, followed by immunoprecipitation with anti-hepatoma poly(A) polymerase antibodies and analysis of the RNAs in the immunoprecipitate, only one labeled small nuclear RNA corresponding to U1 RNA was found. Preimmune sera did not form a complex with U1 RNA. Hepatoma poly(A) polymerase antisera did not immunoprecipitate U1 RNA or any other small nuclear RNA from a cell line (H4-11-EC3) which does not contain the tumor-type poly(A) polymerase. Immunoblot analysis of hepatoma 7777 nuclear extract or purified poly(A) polymerase with anti-ribonucleoprotein antisera did not show any cross-reactivity of the latter sera with poly(A) polymerase. The major RNA immunoprecipitated from the hepatoma nuclear extracts using trimethyl cap (m3G) antisera corresponded to the RNA immunoprecipitated with poly(A) polymerase antisera. These data indicate that U1 RNA is closely associated with poly(A) polymerase and suggest the potential involvement of this RNA in the cleavage/polyadenylation of mRNA precursor.

Regulation of cytoplasmic poly(A) polymerase activity by dihydrotestosterone in the kidney of rat

Polyadenylation of mRNA, a post-transcriptional phenomenon, is catalysed by cytoplasmic and nuclear poly(A) polymerases. During normal growth and development cytoplasmic poly(A) polymerase activity in the kidney of rat increased from day 20 reaching to a peak at 35 days. Dihydrotestosterone at a dose of 500 micrograms and above significantly stimulated the enzyme activity in the cortex of kidney in the castrated animals. A single dose of dihydrotestosterone caused significant increase in the enzyme activity at 12 h after treatment and was maintained till 24 h. Antiandrogen cyproterone acetate inhibited dihydrotestosterone-induced enzyme activity in kidney cortex. These results show that cytoplasmic poly(A) polymerase of rat kidney is regulated by dihydrotestosterone.

Direct inhibitory actions of GnRH on accessory reproductive organs of rat

Recently gonadotropin releasing hormone (GnRH) and its agonistic analogs were demonstrated to have some direct actions in accessory reproductive organs. In our study the effects of GnRH and its analogs on some steroid hormone induced responses were investigated. GnRH and its analogs inhibited estradiol induced ornithine decarboxylase (ODC) and glucosamine-6-phosphate synthase activities in the uterus of rat. These enzymes which are markers for cell proliferation are regulatory enzymes in the biosynthetic pathways of polyamines and glycoproteins, respectively. Similarly, GnRH and its analogs also inhibited testosterone stimulated ODC activity in ventral prostate of rat. In addition, GnRH analog inhibited incorporation of radioactive precursors into RNA and protein induced by estradiol in uterus or dihydrotestosterone (DHT) in ventral prostate. In an effort to elucidate the mechanism of action of GnRH in uterus, it was found that GnRH analog treatment does not alter the estradiol receptor content in vivo. Also, GnRH does not show any effect on radioactive estradiol binding to its receptor in vitro. Hence, the inhibitory actions of GnRH in uterus may not involve estradiol receptors. However, GnRH analogs were found to have post-transcriptional effects. It was observed that DHT induced poly(A) polymerase activity in ventral prostate and estradiol induced poly(A) polymerase activity in uterus were inhibited by GnRH analog treatment. It was further observed that GnRH inhibited incorporation of [3H]uridine into poly(A)+ RNA of ventral prostate. This indicates that the inhibitory effects of GnRH involve post-transcriptional mechanisms.

Inhibition of sex-steroid hormone induced ornithine decarboxylase and poly(A)-polymerase activities by a GnRH agonist in the rat kidney

Recently GnRH and its synthetic agonists were shown to exert extrapituitary actions and inhibit the growth-promoting effects of testosterone and estradiol. In the present study, the long-term effect of GnRH agonist [des-Gly10, D-Ala6-GnRH ethylamide GnRHa] on the steroid-induced renotropic effect was investigated. Gonadectomy of 30-day old male and female rats resulted in the drastic reduction of kidney ornithine decarboxylase (ODC) activity. Injection of testosterone (75 micrograms/rat) or estradiol (1 microgram/rat) to castrated rats significantly increased the enzyme activity at 24 h. Treatment with the GnRH agonist, two doses of 100 micrograms each, caused significant inhibition of the hormone induced ODC activity. Similarly injection of dihydrotestosterone to castrated adult male rats significantly increased poly(A)-polymerase activity at 24 h. Two doses of 100 micrograms of GnRHa caused significant inhibition of DHT induced poly(A)-polymerase activity. These results show that chronic exposure to potent GnRH analogs may have anti-steroidal activity in the kidney.

Effect of gonadotropin releasing hormone on ventral prostate of rat

Testosterone induced increase in ornithine decarboxylase (ODC) activity was inhibited by simultaneous treatment with gonadotropin releasing hormone (GnRH) and its analogue in the ventral prostate of rat. Inhibition of 3H-uridine, 3H-phenylalanine and 3H-leucine incorporation into TCA precipitable material was also inhibited by GnRH in the dihydrotestosterone (DHT) treated animals. These studies further confirm that GnRH acts directly on ventral prostate and causes inhibitory effects.

Androgen regulation of poly(A) polymerase in the ventral prostate of rat

The effect of various hormones on the levels of poly(A) polymerase in the ventral prostate of castrated rats was investigated. It was observed that this enzyme is specifically induced by androgens; progesterone and estradiol-17 beta did not cause stimulation of poly(A) polymerase activity. Dihydrotestosterone-induced poly(A) polymerase was inhibited by cordycepin, actinomycin-D and cycloheximide, which indicates that the genetic transcription leading to the enzyme poly(A) polymerase is regulated by androgens in the ventral prostate.

Inhibition of polyadenylation of mRNA by gonadotropin releasing hormone

The mechanism of extra pituitary inhibitory action of gonadotropin releasing hormone (GnRH) was investigated. Simultaneous injection of GnRH caused dose dependent inhibition of dihydrotestosterone (DHT) induced poly(A) polymerase in the ventral prostate of rat. In addition injection of GnRH to DHT treated animals caused reduced incorporation of 3H-uridine into poly(A)+ mRNA. Since poly(A) segment is known to help in translation of mRNA, it is possible that the inhibitory effect of GnRH is due to the inhibition of polyadenylation of mRNA.