CssRS is a two-component system that plays a pivotal role in mediating the secretion stress response in Bacillus subtilis. This system upregulates the synthesis of membrane-bound HtrA family proteases that cope with misfolded proteins that accumulate within the cell envelope as a result of overexpression or heat shock. Recent studies have shown the induction of CssRS-regulated genes in response to cell envelope stress. We investigated the induction of the CssRS-regulated htrA promoter in the presence of different cell wall- and membrane-active substances and observed induction of the CssRS-controlled genes by glycopeptides (vancomycin and teicoplanin), polymyxins B and E, certain β-lactams, and detergents. Teicoplanin was shown to elicit remarkably stronger induction than vancomycin and polymyxin B. Teicoplanin and polymyxin B induced the spxO gene expression in a CssRS-dependent fashion, resulting in increased activity of Spx, a master regulator of disulfide stress in Bacillus subtilis. The CssRS signaling pathway and Spx activity were demonstrated to be involved in Bacillus subtilis resistance to teicoplanin and polymyxin B.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Bacillus subtilis * genetics drug effects metabolism MeSH
- Bacterial Proteins * genetics metabolism MeSH
- Polymyxin B * pharmacology MeSH
- Promoter Regions, Genetic MeSH
- Gene Expression Regulation, Bacterial * drug effects MeSH
- Signal Transduction MeSH
- Teicoplanin * pharmacology MeSH
- Publication type
- Journal Article MeSH
The ESAT6-like Secretion System (ESS) of the human pathogen Staphylococcus aureus secretes heterodimeric virulence effectors such as EsxB and EsxD. To gain insights into the nature of EsxB-EsxD interaction, randomly mutated esxB generated by error-prone PCR was co-transformed together with esxD as adenylate cyclase fusion constructs into cyclase-deficient Escherichia coli, followed by reverse bacterial two-hybrid screening. Three color species were observed: dark blue, light blue, and white (no EsxB-EsxD interaction). The esxB from white colonies was subjected to standard PCR to check for gene signal, followed by SDS-PAGE for variant stability assessment. The gene coding for a stable EsxB variant that perturbed interaction with EsxD was further subjected to DNA sequencing. A single point mutation in esxB at position 157 was identified, leading to an amino acid change from asparagine to aspartic acid at position 53 in the resulting protein. Structural modeling of EsxB reveals that N53 is surface exposed. Whereas N53S substitution by site-directed mutagenesis retained heterodimerization with EsxD, N53A substitution abrogated such interaction. In addition, N53D change in EsxB did not alter interaction with EssG, another soluble component of the ESS pathway, suggesting minimal impact of the N53D substitution on EsxB stability and solubility. Taken together, these data provide new insights into the nature of EsxB-EsxD interaction and offer a systematic approach for in vivo analysis of protein-protein interactions of pathogenic bacteria in non-pathogenic hosts.
- MeSH
- Bacterial Proteins chemistry genetics metabolism MeSH
- Virulence Factors genetics metabolism MeSH
- Protein Conformation MeSH
- Mutation MeSH
- Mutagenesis * MeSH
- Polymerase Chain Reaction MeSH
- Type VII Secretion Systems genetics metabolism MeSH
- Sequence Alignment MeSH
- Staphylococcus aureus genetics metabolism MeSH
- Two-Hybrid System Techniques MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
Nesteroidní antiflogistika (NSAID) patrí mezi svetove velice casto užívaná léciva. Jsou bežne užívána pri lécbe bolesti a zánetu. Úcinek NSAID spocívá v inhibici enzymu cyklooxygenázy (COX). Tento enzym je zodpovedný za tvorbu prostaglandínu vznikajících z kyseliny arachidonové. Jsou známy dve isoformy cyklooxygenázy – COX-1 a COX-2. COX-1 se nachází v mnoha tkáních a v krevních destickách, kde inhibuje vznik tromaboxanu a tím inhibuje agregaci trombocytu. COX-1 je také zodpovedná za ochranu žaludecní sliznice a udržování renálních funkcí. COX-2 se nachází predevším na místech postižených zánetem. Koxiby jsou nesteroidní antiflogistika, která selektivne blokují COX-2, ne COX-1. Pri lécbe COX-2 inhibitory je výskyt závažných gastrointestinalních komplikací významne nižší než u tradicních NSAID. COX-2 inhibitory se nezdají být renoprotektivní a rovnež neaktivují agregaci trombocytu. Užívání NSAID je omezeno vysokým výskytem nežádoucích ucinku – zejména NSAID gastropatie, renálních syndromu a rizikem vzniku kardiovaskularních príhod, které jsou popsány níže.
Nonsteroidal anti-inflammatory drugs (NSAID) are among the most widely used medications in the world. They are commonly used for the treatment of pain and inflammation associated with various disorders. The effects of NSAIDs are due to the inhibition of the enzyme cyclooxygenase (COX). COX enzyme is responsible for the formation of prostaglandins from arachidonic acid. Two isoenzymes have been identified, COX-1 and COX-2. COX-1 is found in many tissues and blood components such as platelets where inhibits the production of thromboxane and thus inhibits platelet aggregation. COX-1 is responsible for protecting the gastric mucosa and maintaining renal function. COX-2 on the other side is found predominatly at side of inflammation in the body. COXIBs are the NSAIDs that selectively inhibit COX-2 and do not inhibit COX-1. The incidence of serious gastrointestinal complications is significantly lower with selective COX-2 inhibitors versus nonselective NSAIDs. COX-2 inhibitors have not been shown to be renal protective and do not inhibit platelet activation. The use of NSAID is restricted by the high incidence of the side-effects – particulary NSAID gastropathy induction, renal syndromes and risk of cardiovascular events, which are described bellow.
Předložená studie se zabývá hodnocením hladin C1q ve skupině 45 nemocných s lupusem a porovnává je s některými parametry apoptózy lymfocytů a jejich T a B subpopulací. Hladiny C1q složky komplementu byly vyšetřeny metodou radiální imunodifuze podle Manciniové pomocí komerčních kitů, apoptotické indexy lymfocytů průtokovou cytoflowmetrií metodou double staining. Průměrné hodnoty C1q v celém souboru dosahovaly hodnoty 173±44,46 mg/l, medián 180 mg/l, ve dvou případech byly hladiny C1q neměřitelně nízké (pod 23 mg/l), v 6 případech byly hodnoty nad 230 mg/l. Ve skupině aktivních nemocných byly průměrné hodnoty hladin C1q složky komplementu 138 mg/l, SD±43,2 mg/l, s mediánem hodnot 145 mg/l. Ve skupině nemocných s nízkou aktivitou choroby dosahovaly průměrné hodnoty C1q složky 202 mg/l, SD±27,5 mg/l, medián byl 208 mg/l. Ve skupině s lupus nefritidou byly průměrné hodnoty C1q složky komplementu 144 mg/l, SD±31 mg/l, medián 150,1 mg/l. Rozdíly mezi aktivními nemocnými a nemocnými s neaktivní chorobu dosahovaly statisticky významného rozdílu (ANOVA, p=0,0005), stejně jako mezi nemocnými s lupus nefritidou a neaktivními pacienty (ANOVA, p=0,001). Za pomocí regresní analýzy byla nalezena signifikantní korelace mezi hladinou C1q a C3 a C4 složkami komplementu (r= 0,49, resp. 0,42), C1q a apoptotickým indexem CD19 (r=0,4) a dále inverzní korelace mezi C1q a ECLAM a SLEDAI indexy (r=-0,4 a -0,46) a s hladinou antinukleozomálních protilátek (r=-0,42) na 0,001 hladině významnosti a slabá inverzní korelace C1q s apoptotickým indexem lymfocytů a s celkovou fagocytární aktivitou (r= -0,37 a -0,35) na 0,05 hladině spolehlivosti. Nebyla prokázána signifikantní korelace hladin C1q složky s indexem poškození SLICC (r=-0,01, s hladinou anti dsDNA protilátek (r=-0,2) a s apoptotickým zastoupením T lymfocytů (r=0,29). Z klinického hlediska se jeví C1q jako jeden z vhodných parametrů sledování aktivity systémového lupus erythematodes, který může doplnit paletu tradičnějších C3 a C4 složek komplementu.
C1q levels were determined in the group of 45 patients with systemic lupus erythematosus and compared with parameters evaluating apoptosis in lymphocytes and their T and B subpopulations. C1q levels were analysed by radial immunodiffusion according to Mancini using commercial kits, apoptotic indices of lymphocytes were determined by flowcytometry using double staining method. Mean values of C1q in the whole group were 173±44,46 mg/l, median was 180 mg/l, in two cases the levels of C1q were undetectable (below 23 mg/l), and in six cases the levels exceeded 230 mg/l. In the group of active patients the mean levels of complement component C1q reached 138 mg/l, SD±43,2 mg/l, and median was 145 mg/l. In the group of patients with moderate activity the mean levels of C1q reached 202 mg/l, SD±27,5 mg/l, and median was 208 mg/l. In the group of patients with lupus nephritis the mean C1q values were 144 mg/l, SD±31 mg/l, and median was 150.1 mg/l. The differences between active and inactive patients as well as between patients with lupus nephritis and inactive patients were statistically significant (p=0.0005 and p=0.001). Using the regression analysis the significant correlations were found between C1q and C3 and C4 complement component levels (r=0.49 and 0.42), C1q and apoptotic index CD19 (r=0.4), and inverse relations were revealed between C1q and ECLAM or SLEDAI indices (r=-0.4 or -0.46), levels of antinucleosomal antibodies (r=-0.42, p=0.0001), and apoptotic index of lymphocytes or the total phagocytic activity (r=-0.37 or -0.35, p=0.05 for both). No correlations were demonstrated between C1q levels and the index of damage SLICC (r=-0.01), levels of anti dsDNA antibodies (r=-0.2), and number of apoptotic T lymphocytes (r=-0.29). This suggests that C1q could be a suitable parameter for follow-up of the activity of systemic lupus erythematosus, which can add to traditionally used C3 and C4 complement components in clinical practice.
Eustigmatophyte algae represent an interesting model system for the study of the regulation of the excitation energy flow due to their use of violaxanthin both as a major light-harvesting pigment and as the basis of xanthophyll cycle. Fluorescence induction kinetics was studied in an oleaginous marine alga Nannochloropsis oceanica. Nonphotochemical fluorescence quenching was analyzed in detail with respect to the state of the cellular xanthophyll pool. Two components of nonphotochemical fluorescence quenching (NPQ), both dependent on the presence of zeaxanthin, were clearly resolved, denoted as slow and fast NPQ based on kinetics of their formation. The slow component was shown to be in direct proportion to the amount of zeaxanthin, while the fast NPQ component was transiently induced in the presence of membrane potential on subsecond timescales. The applicability of these observations to other eustigmatophyte species is demonstrated by measurements of other representatives of this algal group, both marine and freshwater.
- MeSH
- Fluorescence MeSH
- Photosynthesis MeSH
- Seaweed chemistry MeSH
- Publication type
- Journal Article MeSH
Série dvou přehledných článků se zabývá vzájemnými vztahy imunitního systému a výživy. V této první části jsou popsány imunitní procesy, které mají důležitý vztah k výživě. Zvláště je kladen důraz na vývojové aspekty imunitního systému, které jsou zásadní pro pochopení interakcí složek výživy s imunitním systémem hlavně v prvních měsících a letech života. Popsány jsou též mechanismy orální tolerance. S ohledem na vývojové aspekty je do této první části zařazen i imunologický vliv složek mateřského mléka. Na tuto část navazuje druhý příspěvek série, který se zabývá vlivem jednotlivých složek potravy na imunitu a stručně popisuje imunopatologické stavy, způsobené poruchy vzájemné interakce imunitního systému a složek potravy.
First of the series of two articles deals with the interaction of the immune system and nutrition, with the emphasis on the developmental aspects and the role of the immunity. The evolutionary aspects of the immune system in the first months of life are put in the context with the adequate nutrition during this crucial period. The processes of oral tolerance are also described and the role of the delicate complex interaction of the nutrition and mucosal immunity is emphasized. The first part is followed by the second article of the series that deals with the individual components of the nutrition on the immune system and shortly describes the diseases arising from the pathological interaction of the immunity and nutritional components.
- MeSH
- Research Support as Topic MeSH
- Nutritional Physiological Phenomena MeSH
- Immune System physiology growth & development MeSH
- Immune Tolerance MeSH
- Humans MeSH
- Milk, Human immunology MeSH
- Peyer's Patches immunology MeSH
- Immunity, Mucosal genetics drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
- Comparative Study MeSH
High blood pressure (BP) of spontaneously hypertensive rats (SHR) is maintained by enhanced activity of sympathetic nervous system (SNS), whereas that of Ren-2 transgenic rats (Ren-2 TGR) by increased activity of renin-angiotensin system (RAS). However, both types of hypertension are effectively attenuated by chronic blockade of L-type voltage-dependent calcium channel (L-VDCC). The aim of our study was to evaluate whether the magnitude of BP response elicited by acute nifedipine administration is proportional to the alterations of particular vasoactive systems (SNS, RAS, NO) known to modulate L-VDCC activity. We therefore studied these relationships not only in SHR, in which mean arterial pressure was modified in a wide range of 100-210 mm Hg by chronic antihypertensive treatment (captopril or hydralazine) or its withdrawal, but also in rats with augmented RAS activity such as homozygous Ren-2 TGR, pertussis toxin-treated SHR or L-NAME-treated SHR. In all studied groups the magnitude of BP response to nifedipine was proportional to actual BP level and it closely correlated with BP changes induced by acute combined blockade of RAS and SNS. BP response to nifedipine is also closely related to the degree of relative NO deficiency. This was true for both SNS- and RAS-dependent forms of genetic hypertension, suggesting common mechanisms responsible for enhanced L-VDCC opening and/or their upregulation in hypertensive animals. In conclusions, BP response to nifedipine is proportional to the vasoconstrictor activity exerted by both SNS and RAS, indicating a key importance of these two pressor systems for actual L-VDCC opening necessary for BP maintenance.
- MeSH
- Calcium Channel Blockers pharmacology therapeutic use MeSH
- Hypertension drug therapy physiopathology MeSH
- Blood Pressure drug effects physiology MeSH
- Rats MeSH
- Disease Models, Animal * MeSH
- Random Allocation MeSH
- Nifedipine pharmacology therapeutic use MeSH
- Rats, Inbred SHR MeSH
- Rats, Inbred WKY MeSH
- Rats, Transgenic MeSH
- Renin-Angiotensin System drug effects physiology MeSH
- Sympathetic Nervous System drug effects physiology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- MeSH
- Antigens, Bacterial MeSH
- Bacterial Proteins MeSH
- DNA, Bacterial analysis MeSH
- Virulence Factors MeSH
- Research Support as Topic MeSH
- Genomic Islands genetics MeSH
- Humans MeSH
- Gene Expression Regulation, Bacterial MeSH
- Streptococcus agalactiae genetics pathogenicity MeSH
- Streptococcus pneumoniae genetics MeSH
- Pregnancy MeSH
- Check Tag
- Humans MeSH
- Pregnancy MeSH
- Female MeSH
