Haptoglobin is a plasma protein of mammals that plays a crucial role in vascular homeostasis by binding free haemoglobin released from ruptured red blood cells. Trypanosoma brucei can exploit this by internalising haptoglobin-haemoglobin complex to acquire host haem. Here, we investigated the impact of haptoglobin deficiency (Hp-/-) on T. brucei brucei infection and the parasite ́s capacity to internalise haemoglobin in a Hp-/- mouse model. The infected Hp-/- mice exhibited normal disease progression, with minimal weight loss and no apparent organ pathology, similarly to control mice. While the proteomic profile of mouse sera significantly changed in response to T. b. brucei, no differences in the infection response markers of blood plasma between Hp-/- and control Black mice were observed. Similarly, very few quantitative differences were observed between the proteomes of parasites harvested from Hp-/- and Black mice, including both endogenous proteins and internalised host proteins. While haptoglobin was indeed absent from parasites isolated from Hp-/-mice, haemoglobin peptides were unexpectedly detected in parasites from both Hp-/- and Black mice. Combined, the data support the dispensability of haptoglobin for haemoglobin internalisation by T. b. brucei during infection in mice. Since the trypanosomes knock-outs for their haptoglobin-haemoglobin receptor (HpHbR) internalised significantly less haemoglobin from Hp-/- mice compared to those isolated from Black mice, it suggests that T. b. brucei employs also an HpHbR-independent haptoglobin-mediated mode for haemoglobin internalisation. Our study reveals a so-far hidden flexibility of haemoglobin acquisition by T. b. brucei and offers novel insights into alternative haemoglobin uptake pathways.
- MeSH
- haptoglobiny * genetika metabolismus MeSH
- hemoglobiny * metabolismus MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- myši knockoutované * MeSH
- myši MeSH
- proteomika metody MeSH
- Trypanosoma brucei brucei * metabolismus MeSH
- trypanozomóza africká * parazitologie imunologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Methods of structural mass spectrometry have become more popular to study protein structure and dynamics. Among them, fast photochemical oxidation of proteins (FPOP) has several advantages such as irreversibility of modifications and more facile determination of the site of modification with single residue resolution. In the present study, FPOP analysis was applied to study the hemoglobin (Hb) - haptoglobin (Hp) complex allowing identification of respective regions altered upon the complex formation. FPOP footprinting using a timsTOF Pro mass spectrometer revealed structural information for 84 and 76 residues in Hp and Hb, respectively, including statistically significant differences in the modification extent below 0.3%. The most affected residues upon complex formation were Met76 and Tyr140 in Hbα, and Tyr280 and Trp284 in Hpβ. The data allowed determination of amino acids directly involved in Hb - Hp interactions and those located outside of the interaction interface yet affected by the complex formation. Also, previously modeled interaction between Hb βTrp37 and Hp βPhe292 was not confirmed by our data. Data are available via ProteomeXchange with identifier PXD021621.
- MeSH
- aminokyseliny chemie metabolismus MeSH
- footprinting proteinů metody MeSH
- haptoglobiny chemie metabolismus MeSH
- hemoglobiny chemie metabolismus MeSH
- hmotnostní spektrometrie metody MeSH
- hydroxylový radikál chemie MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- oxidace-redukce MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: To assess vitamin D status and health correlates in a sample of apparently healthy Caucasian participants residing in an urban area, Athens, with latitude 370 58' 0" N and longitude 230 43' 0" E, after taking into consideration a broad range of purported biological, behavioural and environmental factors. METHOD: Men and women 35+ years from a selected population (n = 490) were studied. Participants completed a detailed questionnaire regarding socio-demographic, lifestyle, clinical and dietary characteristics. Biomarkers were measured after 12 h fasting. Linear and multinomial regression models were used to evaluate the association between 25(OH)D and determinants of vitamin D status. RESULTS: Results revealed that one hour increase of sunlight exposure decreased the odds of having D deficiency (i.e., < 20 ng/mL) by 70% (OR = 0.30, 95% Cl: 0.20-0.45), adjusted for age, sex, family status, physical activity, smoking habits, BMI, triglycerides, parathyroid hormone, uric acid, haptoglobin, folate acid and haemoglobin, as compared to sufficient levels (i.e., >30 ng/mL). Regarding biomarkers, parathyroid hormone and haptoglobin were found to be related with the odds of having vitamin D deficiency (OR = 1.11, 95% CI: 1.05-1.16; OR = 1.02, 95% CI: 1.00-1.03, respectively) as compared to the sufficient levels. CONCLUSIONS: Sufficient serum vitamin D levels were observed among participants with characteristics associated with reduced cardiovascular risk, such as normal BMI, increased physical activity, decreased parathyroid hormone and decreased inflammatory markers. Even a slight increase in sunlight exposure could have beneficial effects on serum vitamin D concentrations and eventually on haemoglobin and inflammatory markers levels, thus providing a simple and inexpensive lifestyle intervention that promotes public health.
- MeSH
- analýza rozptylu MeSH
- biologické markery krev MeSH
- dieta MeSH
- dospělí MeSH
- haptoglobiny metabolismus MeSH
- index tělesné hmotnosti MeSH
- lidé středního věku MeSH
- lidé MeSH
- městské obyvatelstvo MeSH
- nedostatek vitaminu D epidemiologie MeSH
- parathormon krev MeSH
- podnebí MeSH
- pohybová aktivita MeSH
- průzkumy a dotazníky MeSH
- regresní analýza MeSH
- rizikové faktory MeSH
- rozdělení chí kvadrát MeSH
- sluneční záření MeSH
- životní styl MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Řecko MeSH
Haptoglobin is a glycoprotein involved in the acute phase response. Previously we reported that haptoglobin gene expression was up-regulated during dietary restriction in young female rats. The present study aimed at determining whether chronic dietary restriction affects haptoglobin blood levels through changing levels and/or activities of IL-6-related transcription factors STAT and C/EBP in the liver as is the case during the acute phase response. To this end, we compared a female Wistar rat model of 50% 6-week-long dietary restriction with the standard laboratory model for the acute phase response induced by turpentine administration. During the turpentine-induced acute phase response, the transitory 5.4-fold increase of rat haptoglobin expression was accompanied by a prominent rise of serum IL-6 concentration and the increased binding of STAT3 and 35kD C/EBPbeta/LAP transcription factors to the haptoglobin gene hormone-responsive element. Results obtained after immunoblotting and DNA affinity chromatography (using hormone-responsive element) suggest that the stable 1.7-fold increase of serum haptoglobin level during dietary restriction was the result of increased amounts and activities of constitutive transcription factors C/EBPalpha and STAT5b, and to a smaller extent of STAT3. When dietary restriction rats were administered turpentine, a 8.7-fold increase in haptoglobin expression was followed by a considerable increase in the amount and hormone-responsive element binding activity of STAT3 but not 35kD C/EBPbeta/LAP. We concluded that haptoglobin gene up-regulation during chronic dietary restriction was regulated by different mechanisms than during the acute phase response, and that it depended on the amount(s) and activit(ies) of transcription factor(s) that characterize low-grade inflammatory conditions.
- MeSH
- chromatografie afinitní MeSH
- dráždivé látky farmakologie MeSH
- financování organizované MeSH
- haptoglobiny genetika metabolismus MeSH
- imunoblotting MeSH
- interleukin-6 krev MeSH
- kalorická restrikce MeSH
- krysa rodu rattus MeSH
- potkani Wistar MeSH
- reakce akutní fáze chemicky indukované metabolismus MeSH
- regulace genové exprese MeSH
- terpentýn farmakologie MeSH
- transkripční faktor STAT3 metabolismus MeSH
- transkripční faktor STAT5 metabolismus MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
Ovarian cancer is the most lethal of all gynecological cancers. Although serum biomarker CA125 is routinely used, there is a need for sensitive and specific complementary biomarkers. N-glycosylation changes in ovarian cancer serum glycoproteins include a decrease in galactosylation of IgG and an increase in sialyl Lewis X (SLex) on haptoglobin ß-chain, ?1-acid glycoprotein and ?1- antichymotrypsin. These changes are also present in chronic inflammations but not in malignant melanoma with low levels of inflammation. Acute phase proteins carrying increased amounts of SLex have an increased half-life. Sialylation of acute phase proteins decreases apoptosis favouring survival of cancer cells. Cancer cells produce inflammatory cytokines which influence glycosylation in liver parenchymal cells. The decreased galactosylation and sialylation of IgG increases cytotoxicity of natural killer cells and complement activation via mannosebinding lectin. Altered glycosylation of acute phase proteins and IgG suggests that cancer regulates certain pathways favouring survival of cancer cells.
- MeSH
- alfa-1-antichymotrypsin krev metabolismus MeSH
- alfa-makroglobuliny metabolismus MeSH
- galaktosa nedostatek MeSH
- glykosylace MeSH
- haptoglobiny metabolismus MeSH
- imunoglobulin G krev metabolismus MeSH
- kyseliny sialové nedostatek MeSH
- lidé MeSH
- metabolismus sacharidů MeSH
- nádorové biomarkery krev MeSH
- nádory vaječníků imunologie metabolismus MeSH
- proteiny akutní fáze metabolismus MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
BACKGROUND: The scavenger receptor for complexes hemoglobin-haptoglobin (CD163), which is expressed on monocytes/ macrophages, is shed to the body fluids in a soluble form (sCD163). OBJECTIVES: To evaluate the dynamics of sCD163 in the blood of patients undergoing cardiac surgery. PATIENTS AND METHODS: Sixty-one adult patients who underwent coronary artery bypass grafting (CABG) were enrolled in the study. They were assigned to undergo CABG using either cardiopulmonary bypass (CPB), "on-pump", (22 patients), modified CPB, mini "on-pump", (17 patients) or without CPB, "off-pump", (22 patients) surgery. Serum levels of sCD163 in venous blood samples taken before and after surgery, and during an early postoperative period, were evaluated by Macro 163(TM) diagnostic kit (IQ Products, Groningen, NL). RESULTS: Compared to the preoperative levels ("on-pump"; 344 ng/mL, "off-pump"; 314.5 ng/mL, mini-invasive "on-pump"; 336.5 ng/mL) serum levels were elevated at the finish of surgery, reaching maximum at the 1(st) postoperative day ("onpump"; 658 ng/mL; p<0.05, "off-pump"; 810.5 ng/mL; p<0.01; mini-invasive "on-pump"; 663 ng/mL; non-significant).No significant differences regarding the serum levels of sCD163 between different surgical approaches were found. CONCLUSION: Serum level of sCD163 scavenger molecule for hemoglobin is elevated at the end of surgery and at the 1(st) postoperative day, being little influenced by cardiopulmonary bypass.
- MeSH
- antigeny diferenciační myelomonocytární krev MeSH
- CD antigeny krev MeSH
- haptoglobiny metabolismus MeSH
- hemoglobiny metabolismus MeSH
- kardiopulmonální bypass škodlivé účinky MeSH
- koronární bypass škodlivé účinky MeSH
- lidé středního věku MeSH
- lidé MeSH
- receptory buněčného povrchu krev MeSH
- senioři MeSH
- zánět etiologie krev MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
A recombinant plasmid containing a 6.5-kb fragment of nontypeable Haemophilus influenzae (NTHI) chromosomal DNA was shown to confer a hemoglobin-haptoglobin-binding phenotype on Escherichia coli. Use of a mini-Tn10kan transposon for random insertion mutagenesis of this recombinant plasmid allowed localization of the NTHI DNA responsible for this hemoglobin-haptoglobin-binding phenotype to a 3.5-kb PstI-XhoI fragment within the 6.5-kb NTHI DNA insert. When this mutagenized NTHI DNA fragment was used to transform the wild-type NTHI strain, the resultant kanamycin-resistant mutant exhibited significantly decreased abilities to bind hemoglobin-haptoglobin and utilize it as a source of heme for aerobic growth in vitro. This mutant also lacked expression of a 115-kDa outer membrane protein that was present in the wild-type parent strain. Transformation of this mutant with wild-type NTHI chromosomal DNA restored the abilities to bind and utilize hemoglobin-haptoglobin and to express the 115-kDa outer membrane protein. Nucleotide sequence analysis of the relevant NTHI DNA revealed the presence of a gene, designated hhuA, that encoded a predicted 117,145-Da protein. The HhuA protein exhibited features typical of a TonB-dependent outer membrane receptor and had significant identity with the hemoglobin receptors of both Haemophilus ducreyi and Neisseria meningitidis.
- MeSH
- bakteriální geny MeSH
- DNA bakterií genetika MeSH
- Haemophilus influenzae genetika metabolismus MeSH
- haptoglobiny * metabolismus MeSH
- hem metabolismus MeSH
- hemoglobiny * metabolismus MeSH
- inzerční mutageneze MeSH
- klonování DNA MeSH
- molekulární sekvence - údaje MeSH
- proteiny vnější bakteriální membrány genetika metabolismus MeSH
- restrikční mapování MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční homologie aminokyselin MeSH
- sekvenční seřazení MeSH
- Publikační typ
- Research Support, U.S. Gov't, P.H.S. MeSH
- srovnávací studie MeSH
