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PubMed1977

The frequency in Japanese of genetic variants of 22 proteins. I. Albumin, ceruloplasmin, haptoglobin, and transferrin.

This paper presents the results of an electrophoretic survey of approximately 4000 individuals from the cities of Hiroshima and Nagasaki, Japan, for four serum proteins: albumin, ceruloplasmin, haptoglobin and transferrin. The haptoglobin gene frequencies obtained for the HP1-HP2 polymorphism are in agreement with earlier reports. Rare electrophoretic variants of albumin, ceruloplasmin and haptoglobin occur with frequencies of 2-48, 0-50 and 0-58 per 1000 determinations, respectively. The noteworthy finding of 8 distinct transferrin variants in these populations, with a combined frequency of 20-90 per 1000 determinations, is also presented. Four of these variants (Dchi, B1, B3, and DHIR2 which corresponds electrophoretically to D4) have been reported in other populations in Japan, but the other five have not previously been differentiated.

Blood Protein Electrophoresis↗
PubMedDate not supplied

[Haptoglobin and ceruloplasmin in systemic scleroderma].

Content of haptoglobin and ceruloplasmin was estimated in blood serum of 23 patients with sclerodermia systematica. A statistically distinct decrease in ceruloplasmin concentration was observed in blood of the patients, whereas content of haptoglobin was markedly increased; this phenomenon reflects a level of the pathological process activity. The proteins are synthesized in various zones of liver lobes: haptoglobin--in the central zone, ceruloplasmin - in the peripheral one. Decrease in content of ceruloplasmin in blood of patients with sclerodermia systematica was due to impairment of hepatocytes, localized in peripheral parts of liver lobes.

Animals↗
PubMed1979

Effects of bacterial endotoxin and corticosteroids on plasma concentrations of alpha 2 macroglobulin, haptoglobin and fibrinogen in rats.

Bacterial endotoxin injected into rats resulted in increased plasma concentration of alpha 2 macroglobulin, haptoglobin and fibrinogen. Cortisone acetate injected i.m. by itself was sufficient to increase the plasma concentration of haptoglobin by 54% and to a lesser extent the concentrations of the other two proteins. When cortisone acetate and/or cortisol succinate were injected simultaneously with varying doses of endotoxin, the effects of the corticosteroid differed for each plasma protein. Doubtless because of the effect of cortisone by itself the slope of the dose-response relationship for haptoglobin was greatly reduced. In contrast to this the slope for alpha 2 macroglobulin was reduced and that for fibrinogen was unaffected. These findings suggest that, if effects due to endogenous corticosteroids are to be avoided, increases in plasma fibrinogen will serve best as indicators of stimulation of the acute-phase response. Since, however, the relative increase of alpha 2 macroglobulin due to the lowest dose of endotoxin was much greater than that of fibrinogen, increases in concentration of the former protein represent the most sensitive indication of the acute-phase response. Consideration of the responses in individual rats has made possible division into those with more or less than average increases for all 3 plasma proteins and those showing irregular responses. Especially in the group which had received the lowest dose of endotoxin, a much larger number than would be expected on a random basis was found to respond regularly with either more or less than average increases for all 3 proteins.

Animals↗
PubMedDate not supplied

Haptoglobin is a Sertoli cell product in the rat seminiferous epithelium: its purification and regulation.

Using multiple HPLC steps, a protein of 67 kDa (estimated by gel permeation HPLC) was purified from Sertoli cell-enriched culture medium that consisted of two dissimilar subunits of 9 (alpha chain) and 24 (beta chain) kDa on SDS-polyacrylamide under reducing conditions. Direct protein sequence analysis of the 9-kDa subunit revealed a sequence of NH2-VELGNDATDIEXD, which is identical to the alpha subunit of the rat haptoglobin (Hp). Hp is a 67-kDa tetrameric serum acute-phase protein consisting of two alpha and two beta subunits (alpha2beta2) of 8.5 kDa and 24.5 kDa, respectively. Using a 351-bp cDNA coding for Hp for northerns and two Hp primers for RT-PCR, we have demonstrated the expression of Hp in Sertoli and Leydig cells, germ cells, and the testis, but not in the epididymis. In contrast to the hepatic haptoglobin, an acute-phase protein whose steady-state mRNA level increased by as much as fivefold during induced inflammation, the testicular homolog reduced by fourfold within 24 hours following induced inflammation, suggesting that this gene is regulated differently in the testis and in the liver. Moreover, the testicular steady-state Hp mRNA level increased steadily after birth during maturation, suggesting its involvement in spermatogenesis. Using primary Sertoli cell cultures in vitro, it was found that the Sertoli cell Hp expression was not regulated by either FSH, testosterone, estradiol, dexamethasone, interleukin-1beta (IL-1beta), IL-6, interferon-gamma (INF-gamma), transforming growth factor-beta (TGF-beta), lymphocyte inhibitory factor (LIF), or germ-cell-conditioned medium (GCCM). Since transferrin secreted by Sertoli cells is an important molecule in maintaining the crucial iron level necessary for spermatogenesis, the identification of haptoglobin as a Sertoli and germ cell product adds a new member to the growing family of metal transporters in the testis that are likely to play an important role in iron metabolism in the testis.

Acute-Phase Reaction↗
PubMed2000

Reference distributions for the positive acute phase serum proteins, alpha1-acid glycoprotein (orosomucoid), alpha1-antitrypsin, and haptoglobin: a practical, simple, and clinically relevant approach in a large cohort.

Most clinical conditions are accompanied by corresponding changes in serum levels of some, if not all, of the acute phase proteins. While conditions that affect the acute phase proteins are usually inflammatory in nature, non-inflammatory conditions also can cause changes (e.g., malnutrition, some malignancies without secondary inflammation, and genetic polymorphism). Only after the confounding effects of non-inflammatory conditions are taken into account can these measurements be used to detect and stage the inflammatory process and to evaluate the impact of treatment. In this third article in a series, reference ranges for serum levels for three of the acute phase proteins that increase during inflammation are examined: alpha1-acid glycoprotein (orosomucoid), alpha-antitrypsin, and haptoglobin. The study is based on a cohort of 55,199 Caucasian individuals from northern New England, tested in our laboratory between 1994 and 1999. Measurements were standardized against CRM 470 (RPPHS) and analyzed using a previously described statistical approach. Individuals with unequivocal laboratory evidence of inflammation (C-reactive protein of 10 mg/l or higher) were excluded. Levels of a,-acid glycoprotein changed little during life and between the sexes. Levels of alpha1-antitrypsin varied somewhat by age, rising slightly beyond age 55; males followed a pattern similar to that for females. For this protein, it was necessary to apply two equations to describe the lower levels associated with certain phenotypes. Haptoglobin levels fell significantly during the first decade of life for both males and females and climbed thereafter. Males and females displayed a similar pattern. When values were expressed as multiples of the age- and gender-specific median levels, the resulting distributions fitted a log-Gaussian distribution well over a broad range. When patient data are normalized in this manner, the distribution parameters can be used to assign a centile corresponding to an individual's measurement, thus simplifying interpretation.

Adolescent↗
PubMed1988

The genetic haptoglobin polymorphism: relevance of paternity assessment.

A practical method for haptoglobin subtyping is described utilizing fast sample preparation by means of batch adsorption to DEAE-cellulose and subsequent isoelectric focusing of reductively cleaved samples. The expanded haptoglobin polymorphism leads to an increase of the theoretical paternity exclusion rate to approximately 33%. Hence, the system appears to be highly attractive for paternity assessment.

Haptoglobins↗
PubMed1987

The human haptoglobin gene: transcriptional regulation during development and acute phase induction.

Haptoglobin is a plasma protein scarcely present in fetal but abundant in adult serum, where it is present at a concentration of approximately 150 mg/100 ml. In this paper we show by run-on experiments that the haptoglobin (Hp) gene is actively transcribed in adult but not in fetal liver nuclei. Studies with established cell lines indicate that the Hp gene is expressed in the hepatoma cells HepG2 but not in the hepatoma cell line Hep3B nor in HeLa cells. Plasmids carrying various segments of the 5' flanking region of the Hp gene fused to the chloramphenicol acetyl transferase (CAT) gene direct CAT transcription when introduced into HepG2 but are inactive in Hep3B and in HeLa cells, thus behaving like the resident chromosomal Hp gene. Deletion analysis defines a region, upstream to the transcription initiation site, essential for cell-specific expression. The Hp gene is induced in Hep3B cells by treatment with supernatant from LPS-stimulated monocytes (SMS), in a manner mimicking the acute phase reaction. We characterize the DNA segment necessary and sufficient for cell-specific expression of the Hp-CAT constructions in HepG2 and show that the same segment is also sufficient for acute phase induction in Hep3B.

Adult↗
PubMed2002

Obesity modulates the expression of haptoglobin in the white adipose tissue via TNFalpha.

Increase in adipose mass results in obesity and modulation of several factors in white adipose tissue (WAT). Two important examples are tumor necrosis factor alpha (TNFalpha) and leptin, both of which are upregulated in adipose tissue in obesity. In order to isolate genes differentially expressed in the WAT of genetically obese db/db mice compared to their lean littermates, we performed RNA fingerprinting and identified haptoglobin (Hp), which is significantly upregulated in the obese animals. Hp is a glycoprotein induced by a number of cytokines, LPS (Lipopolysaccharide), and more generally by inflammation. A significant upregulation of WAT Hp expression was also evident in several experimental obese models including the yellow agouti (/) A(y), ob/ob and goldthioglucose-treated mice (10-, 8-, and 7-fold, respectively). To identify the potential signals for an increase in Hp expression in obesity, we examined leptin and TNFalpha in vivo. Wild type animals treated with recombinant leptin did not show any alteration in WAT Hp expression compared to controls that were food restricted to the level of intake of the treated animals. On the other hand, Hp expression was induced in mice transgenically expressing TNFalpha in adipose tissue. Finally, a significant downregulation of WAT Hp mRNA was observed in ob/ob mice deficient in TNFalpha function, when compared to the ob/ob controls. These results demonstrate that haptoglobin expression in WAT is increased in obesity in rodents and TNFalpha is an important signal for this regulation.

Adipocytes↗
PubMed1995

Purification of a 240 kDa protein from serum and follicular fluid of water buffalo and its identification as haptoglobin.

The fluids from healthy growing follicles of water buffalo were previously found free of the polypeptides H (M(r) 36,000) and L (M(r) 21,000) which were instead detected in fluids from atretic follicles and blood. Here we report evidence that these two polypeptides, as selected from serum by specific anti-L antibodies, are the subunits of an oligomeric protein. The protein was purified from serum or follicular fluid, and its molecular weight (240 kDa), isoelectric point (6.5), and amino acid composition were determined. The NH2-terminal sequences of the subunits L and H were analyzed: 100% and 90% homology with alpha and beta chains of bovine haptoglobin, respectively, was found. Thus, haptoglobin can be used as a novel molecular marker to assess the physiological state of the blood-follicle barrier or discriminate between atretic and healthy follicles.

Amino Acids↗
PubMed1995

Expression and inflammatory regulation of haptoglobin gene in adipocytes.

Haptoglobin (HP) is the major hemoglobin binding protein which is synthesized mainly in the liver. It functions to prevent iron loss and kidney damage in human and other mammals. Recently, HP has been shown to possess antioxidant and angiogenic properties. As one of the major acute phase reactants, HP's levels in plasma increase significantly during inflammation, infection and malignancy. In this study, high levels of HP mRNA were found to be transcribed by adipocytes in addition to liver cells in mice. After inflammation had been induced in vivo, expression of the haptoglobin gene rose six-fold in adipose tissue, an increase compatible with that observed in the normal mouse liver. The expression of HP by adipocytes presents new directions in which HP's role as an antioxidant or as an angiogenic factor can be investigated.

Adipocytes↗
PubMed1996

Differences between normal and autoimmune T cell responses to autologous erythrocytes and haemoglobin: impairment of haptoglobin-mediated inhibition in NZB spleen cells.

Helper T cells are required for development of the autoantibody responses to native mouse erythrocytes (MRBC) that spontaneously develop in NZB mice. However, the stimulus for these Th is not known. Therefore, we compared the abilities of splenic T cells from actively autoimmune old NZB mice and preautoimmune, young NZB mice with those of T cells from nonautoimmune strains of mice to respond to autologous erythrocytes. We found that autologous RBC ghosts, washed free of haemoglobin, induced low, but statistically significant, proliferative responses in T cells from old NZB mice but not in T cells from young NZB or from normal young and old BALB/c mice. In addition, autologous RBC lysates induced proliferative responses detectable by 3H-thymidine uptake in T cells from nonautoimmune as well as autoimmune mice. CD4+ T cells accounted for most of the observed RBC lysate-induced proliferation, with virtually no response made by CD8+ T cells or B cells. T cells from actively autoimmune NZB mice were not more active in their responses to RBC lysates than T cells from normal strains of mice in terms of their level of proliferation, kinetics, or dose response. Haemoglobin was the major stimulus in the autologous RBC lysates and a similar stimulation was seen with lysates and haemoglobins from horse, human, and mouse sources. Haptoglobin, a haemoglobin-binding serum protein, inhibited T cell responses to haemoglobin and haemoglobin-containing RBC lysates but did not have the same effect on these responses in T cells from either young or old NZB mice. Therefore, either or both of the RBC stimuli from autologous RBC might account for the helper T cell activity in autoimmune NZB mice. T cells in normal mice do not respond either to RBC lysates in the presence of haptoglobin or to RBC ghosts.

Animals↗
PubMed1994

Utilization of haem from the haptoglobin-haemoglobin complex by Bacteroides fragilis.

Possession of specialized iron acquisition systems is a prerequisite for the survival of pathogenic bacteria in their host. The purpose of this study was to determine whether Bacteroides fragilis, a clinically important Gram-negative anaerobic bacterium, possesses a specific haem-uptake system. Growth studies indicated that this microorganism can utilize haem from either haemoglobin or haptoglobin-haemoglobin as its sole source of iron. Iron-repressible haem-binding protein complexes (HBP complexes), involved in the uptake of haem from haptoglobin-haemoglobin were detected by means of lithium dodecyl sulfate polyacrylamide gel electrophoresis (LDS-PAGE). Four polypeptides of approximately 60, 58, 49 and 35 kDa, which are part of these HBP complexes, were identified as haem-binding proteins. A 44 kDa iron-repressible outer-membrane protein is needed for a functional HBP complex, but the exact role of this protein in the uptake of haem is still unknown.

Bacteroides fragilis↗
PubMed1989

Haptoglobin subtyping by isoelectric focusing in ultrathin-layer polyacrylamide gels. Population genetic data for Hanover and Lower Saxony.

This report describes a method for subtyping haptoglobin by means of isoelectric focusing in 0.2-mm ultrathin-layer polyacrylamide gels. Haptoglobin (Hp) is purified by ion-exchange chromatography and reduced. The well-known advantages of ultrathin-layer gels combine high isoelectrophoretic resolution of the Hp subtypes with less demands for time and material and make sequential visualization by fixation and protein staining possible. The distribution of the Hp subtypes in 1500 unrelated adults from Hanover and Lower Saxony is presented. Allelic frequencies are calculated to be: Hp*2FF = 0.0030; *2FS = 0.5620; *2SS = 0.0290; *1F = 0.1537; *1S = 0.2523. Segregation analysis for 68 matings shows an autosomal codominant mode of transmission in all cases. For the population investigated the chance of isolated paternity exclusion with the subtyped Hp system amounts to 33.91%.

Electrophoresis, Polyacrylamide Gel↗
PubMed1983

Types and subtypes of haptoglobin in the Chinese population.

Haptoglobin phenotypes of 1121 unrelated Chinese blood donors in Beijing were determined. The gene frequency of Hp1 was 0.270. A rare variant, which we identified as Hp1S-J, was found. Two hundred and two samples of this population were submitted to haptoglobin subtyping, and no Hp1F allele was found among them.

Blood Donors↗
PubMed1990

An improved method for the study of equine haptoglobin heterogeneity.

Equine serum haptoglobin was separated by polyacrylamide gel isoelectric focusing and visualized by protein staining or Western blotting. Conventional protein staining revealed up to three bands in the pI range 4.17 to 4.44. The blotting technique, however, showed an anodal group of 8 to 10 bands with a pI range of 4.11 to 4.52 and a cathodal group of 4 to 6 bands with a range of 4.55 to 5.14. The blotting method revealed that equine haptoglobin migrates outside the prealbumin area, in contrast to previous reports.

Animals↗
PubMed1991

Shared genetic susceptibility of type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus: contributions of HLA and haptoglobin.

Epidemiologic data suggest that having a parent with Type 2 (non-insulin-dependent) diabetes mellitus increases the risk for Type 1 (insulin-dependent) diabetes in siblings of a Type 1 diabetes proband. This increase in risk is consistent with a shared genetic susceptibility between Type 1 diabetes and Type 2 diabetes. We contrast genetic risk factors in three sets of families, consisting of (1) a single Type 1 diabetic child (proband) and non-diabetic parents, (2) multiple Type 1 diabetic siblings and non-diabetic parents, and (3) at least one Type 1 diabetic child and at least one Type 2 diabetic parent. Previous studies have demonstrated that HLA region genes, which elevate the risk in Type 1 diabetes, have no significant effect with respect to the risk for developing Type 2 diabetes. An earlier report cited a contribution by the haptoglobin locus to genetic susceptibility for Type 2 diabetes. We provide evidence that a high risk HLA antigen (HLA-DR3) is decreased to a greater extent in Type 1 patients with a Type 2 parent than in Type 1 patients in which the parents are not diabetic. The role of HLA-DR4 is maintained in these families, with an unexpectedly significant increased rate of transmission of the HLA-DR4 allele from Type 2 parent to Type 1 offspring. The role of haptoglobin in these families does not appear to be important, either with respect to association with diabetes or with respect to linkage with a secondary susceptibility locus. These results indicate that families with a Type 2 parent and Type 1 child, heavily determined by HLA-DR4 linked factors, may represent a homogeneous subset of diabetes susceptibility.

Adult↗
PubMed1986

The alpha 2 cDNA sequence of human haptoglobin carries a bacterial promoter functional in vivo.

Various constructions of human haptoglobin (Hp) cDNA coding either for the complete alpha 2FS beta precursor protein or only for the beta subunit have been placed under the control of the lambda PR promoter in the bacterial expression vector pCQV2 (Queen, 1983). In addition to the expected 45,000 dalton polypeptide synthesized after induction of the PR promoter, the complete alpha 2FS beta constructions constitutively express a smaller polypeptide of approximately 30,000 dalton corresponding to a truncated Hp protein. Computer analysis of the HpcDNA revealed the presence of two strong potential bacterial promoters (alpha 2 PF and alpha 2 PS) located in the duplicated alpha 2FS sequence. Both Hp promoter signals are followed by potential mRNA start sites and ribosome binding sites at a compatible distance from initiation codons. In addition, the Hp alpha 2 cDNA sequence, when fused upstream to the cDNA coding for alpha 1-antitrypsin, constitutively promotes in vivo the efficient expression of an hybrid protein specifically recognized by antibodies raised against alpha 1-antitrypsin or haptoglobin.

Cloning, Molecular↗
PubMed1993

Identification of an uncommon haptoglobin type using DNA and protein analysis.

The inherited variations in haptoglobin phenotypes are attributed to the homozygous and heterozygous combinations of three common autosomal alleles: HP*1F, HP*1S and HP*2. HP*1F and HP*1S encode polypeptides that differ by two amino acids at positions 51 and 53. The formation of HP*2 is postulated to have resulted from a breakage and subsequent reunion event at non-homologous positions of two HP*1 alleles. The most common form of HP*2 is HP*2FS in which the 5' end of HP*2 resembles HP*1F and the 3' end resembles HP*1S. Homologous crossing over between HP*2 and either an HP*1F or HP*1S allele in HP*2/HP*1 heterozygotes can change the usual type of HP*2 to three other forms: HP*2SS, HP*2FF or HP*2SF. We describe a nuclear family in which the uncommon genotype HP*2SS is one parent caused initial confusion in assigning genotypes to the rest of the nuclear family. The data demonstrate the need for a cautious approach when deducing haptoglobin genotypes from molecular analysis alone.

Alleles↗