Ribozyme-mediated specific gene replacement of the alpha1-antitrypsin gene in human hepatoma cells.

BACKGROUND/AIMS: Some of the mutant forms of cellular proteins not only lose their function, but also cause diseases by their toxic effects. One of the challenging tasks in the field of gene therapy will be "gene replacement" accomplished by inhibiting mutant gene expression and providing normal function of the same gene, simultaneously. Although lung involvement in alpha1-antrypsin (alpha1-AT) deficiency is caused by the lack of alpha1-AT function, the liver involvement is due to the accumulation of the mutated alpha1-AT protein. Therefore, one possible approach to prevent and treat the disease manifestations of alpha1-AT deficiency is to inhibit the expression of the mutated gene and replace it with normally functioning alpha1-AT protein in the liver. METHODS: For the inhibition of alpha1-AT gene expression, panels of alpha1-AT-specific hammerhead ribozymes designed to target different GUC sites in the alpha1-AT mRNA were evaluated in a human hepatoma cell-line, transduced with retroviral vectors which express ribozymes under the control of a human tRNA promoter. A bi-functional vector was also constructed, which contained a functional alpha1-AT ribozyme and was combined with a modified alpha1-AT gene, whose product was engineered to be resistant to the specific alpha1-AT ribozyme. This construct was transduced into target hepatoma cells. RESULTS: The transduced hepatoma cells showed the effective expression of modified alpha1-AT, under the conditions where the endogenous alpha1-AT gene expression was inhibited. CONCLUSION: This ribozyme-mediated, specific gene replacement is a first step in the gene therapy of alpha1-AT deficiency.     

Two polymorphisms in the glucocorticoid receptor gene directly affect glucocorticoid-regulated gene expression

CONTEXT: Interindividual variation in glucocorticoid (GC)-sensitivity can be partly explained by polymorphisms in the GC receptor (GR) gene. The ER22/23EK and N363S polymorphisms have been described to be associated with lower and higher GC sensitivity, respectively. OBJECTIVE AND DESIGN: We examined the basis of this altered GC sensitivity by expressing GR(N363S) and GR(ER22/23EK) in COS-1 cells and investigating their transactivating and transrepressing capacities using a GC response element-luciferase reporter and a p65-activated nuclear factor kappaB-luciferase reporter, respectively. Furthermore, we evaluated the transactivating and transrepressing capacities of the GR in peripheral blood mononuclear lymphocytes of homozygous and heterozygous carriers of these polymorphisms by determining the maximum effect of dexamethasone on transactivation of the GC-induced leucine-zipper and transinhibition of the IL-2 gene by means of real-time RT-PCR. RESULTS: The effects of the polymorphisms in the GR gene previously observed in population studies were also detected at the level of gene expression. The ER22/23EK polymorphism resulted in a significant reduction of transactivating capacity, in both transfection experiments (-14 +/- 5%, P < 0.05) and peripheral blood mononuclear lymphocytes of carriers of this polymorphism (homozygous: -48 +/- 6%, P < 0.01, n = 1; heterozygous: -21 +/- 4%, P = 0.08, n = 3). The N363S polymorphism, associated with increased GC sensitivity, resulted in a significantly increased transactivating capacity, both in vitro (8 +/- 3%; P < 0.02) and ex vivo (homozygous: 204 +/- 19%, P < 0.0001, n = 1; heterozygous: 124 +/- 8%, P = 0.05, n = 3). Neither the ER22/23EK nor the N363S polymorphism seemed to influence the transrepressing capacity of the GR. CONCLUSION: The presence of these and other GC sensitivity-modulating polymorphisms may have consequences for the use of GCs in a clinical setting.     

A polymorphism in the gene encoding AdipoR1 affects olfactory recognition

Polymorphisms in the gene encoding adiponectin receptor 1 (AdipoR1) are associated with insulin resistance, fatty liver, increased risk for type 2 diabetes and cardiovascular disease. AdipoR1 is expressed in the central nervous system and in the olfactory mucosa of mice and humans. We therefore hypothesized that a common polymorphism in AdipoR1 might alter olfactory function. We investigated a group of 222 healthy subjects (male: n = 147, female: n = 75) for olfactory recognition, and genotyped them for the polymorphism rs6666089 in the human AdipoR1 gene. This polymorphism has been previously shown to be associated with insulin resistance. Olfactory recognition was tested using standardized sniffing sticks, and parameters of glucose metabolism and serum adiponectin levels were assessed. We found a significant olfactory impairment in carriers of the AdipoR1 polymorphism rs6666089 (olfactory recognition: GG: 89.4 ± 1.2%, GA: 86.9 ± 1.4%, AA: 77.2 ± 4.8%, additive model, P = 0.0004, adjusted for age). Adiponectin levels had no impact on olfactory recognition. Fasting plasma glucose, fasting plasma insulin, body mass index and HbA1c did not differ between the genotype groups. In conclusion, the presence of a genetic variation in AdipoR1 is associated with decreased olfactory recognition in healthy subjects. Adiponectin signalling may have an important role in olfactory function and regulation of appetite.     

Somatic mutations of the trefoil factor family 1 gene in gastric cancer

BACKGROUND & AIMS: There is increasing evidence that trefoil factor family 1 (TFF1) is a stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents. TFF1 knockout mice developed multiple gastric adenomas and carcinomas, suggesting that TFF1 is a gastric-specific tumor-suppressor gene. METHODS: We analyzed the somatic mutations and loss of heterozygosity (LOH) of the TFF1 gene using an intragenic polymorphic marker in 61 gastric tumors. The expression pattern of TFF1 was also examined by immunohistochemistry. RESULTS: We detected a total of 8 somatic mutations-1 (5.5%) of 18 adenomas and 7 (16.3%) of 43 carcinomas-that were all missense mutations confined to the loop I and loop II structure of TFF1. We detected LOH in 5 (1 in adenoma and 4 in cancer) of 30 (16.7%) informative gastric tumors with an intragenic polymorphic marker -2 base pairs (bp) upstream of the coding region of the TFF1 gene. Although 2 cases were noninformative, the 7 gastric cancers with mutation seemed to show the loss of the remaining allele except in 1 case, suggesting that TFF1 is a tumor-suppressor gene. We found loss of TFF1 expression in 44.2% of the gastric carcinomas, but there is no correlation between immunoreactivity and genetic alterations of the TFF1 gene. CONCLUSIONS: These results indicate that genetic alterations of TFF1 may lead to gastric mucosal barrier defects and contribute to the pathogenesis of gastric cancer.     

Association analysis of the vitamin D receptor gene, the type I collagen gene COL1A1, and the estrogen receptor gene in idiopathic osteoarthritis

OBJECTIVE: Evidence has accumulated supporting a role for genes in the etiology of osteoarthritis (OA). Several candidates have been targeted as potential susceptibility loci including genes that are involved in the regulation of bone density. Genetic association analysis has suggested a role for the vitamin D receptor gene (VDR) and the estrogen receptor gene (ER) in susceptibility. Such findings must be tested in additional independent cohorts. We tested for association of these 2 genes, plus a third gene implicated in bone density, COL1A1, with idiopathic OA. METHODS: A case-control cohort of 371 affected probands and 369 unaffected spouses was used. Association was tested using 4 intragenic single nucleotide polymorphisms (SNP), one each for the VDR and COL1A1 genes, and 2 for the ER gene. The VDR and ER SNP are the same SNP that have been associated with OA. All 4 SNP affect restriction enzyme sites and were genotyped using polymerase chain reaction and enzyme digestion. Allele and genotype distributions for each SNP were compared between cases and controls and analyzed using Fisher's exact test. RESULTS: There was no evidence of association of the VDR or the ER gene SNP to OA. There was weak evidence of association of the COL1A1 SNP in female cases (p = 0.017), reflected by a difference in the distribution of genotypes at this SNP between female cases and controls (p = 0.027). However, when corrected for multiple testing, these results were not significant. CONCLUSION: If the VDR, ER, or COL1A1 genes do encode predisposition to OA then the 4 SNP tested are not associated with major susceptibility alleles at these 3 loci.     

Assessment of the interleukin 1 gene cluster and other candidate gene polymorphisms in host susceptibility to tuberculosis

Setting: A study of tuberculosis cases and healthy blood donor controls from the Western Region of The Gambia, West Africa.Objective: To investigate the potential role of candidate gene polymorphisms in host susceptibility to tuberculosis.Design: Single base change polymorphisms in interleukin 1 beta (IL1β), interleukin 10 (IL10) and fucosyltransferase-2 (FUT-2), microsatellite polymorphisms in interleukin 1 alpha (IL1α) and IL10 and a minisatellite polymorphism in interleukin 1 receptor antagonist (IL1RA) were typed in over 400 tuberculosis cases and 400 healthy blood donor controls.Results: IL1 gene cluster polymorphisms (IL1RA and possibly IL1α) showed marginally significant association with tuberculosis. In particular IL1RA allele 2 heterozygotes were less frequent among tuberculosis cases than controls (P= 0.03). IL1β, IL10 and FUT-2 polymorphisms were not associated with tuberculosis.Conclusion: Genetic susceptibility to tuberculosis among Gambians may be partly determined by genes in the IL1 gene cluster on chromosome 2. Further association studies will be required on other population groups to confirm whether these results are of biological significance.     

Assessment of the interleukin 1 gene cluster and other candidate gene polymorphisms in host susceptibility to tuberculosis.

SETTING: A study of tuberculosis cases and healthy blood donor controls from the Western Region of The Gambia, West Africa. OBJECTIVE: To investigate the potential role of candidate gene polymorphisms in host susceptibility to tuberculosis. DESIGN: Single base change polymorphisms in interleukin 1 beta (IL1 beta), interleukin 10 (IL10) and fucosyltransferase-2 (FUT-2), microsatellite polymorphisms in interleukin 1 alpha (IL1 alpha) and IL10 and a minisatellite polymorphism in interleukin 1 receptor antagonist (IL1RA) were typed in over 400 tuberculosis cases and 400 healthy blood donor controls. RESULTS: IL1 gene cluster polymorphisms (IL1RA and possibly IL1 alpha) showed marginally significant association with tuberculosis. In particular IL1RA allele 2 heterozygotes were less frequent among tuberculosis cases than controls (P = 0.03). IL1 beta, IL10 and FUT-2 polymorphisms were not associated with tuberculosis. CONCLUSION: Genetic susceptibility to tuberculosis among Gambians may be partly determined by genes in the IL1 gene cluster on chromosome 2. Further association studies will be required on other population groups to confirm whether these results are of biological significance.     

Polymorphism in the interleukin-1 receptor antagonist gene is associated with alcoholism in Spanish men

BACKGROUND: A polymorphism located in intron 2 of the interleukin-1 receptor antagonist (IL1RN) gene recently has been associated with the development of hepatic fibrosis in Japanese alcoholics. In the present study, we analyzed whether there is an association between this polymorphism, alcoholism, and alcoholic liver disease in a Spanish male population of alcoholics. METHODS: The IL1RN genotype was assessed by polymerase chain reaction by using oligonucleotides that flank a variable nucleotide tandem repeat polymorphism located in intron 2 of this gene in 90 male alcoholic patients from Spain: 30 alcohol-dependent men, 30 alcohol abusers, and 30 alcoholics with liver cirrhosis. We also studied 40 healthy subjects. RESULTS: The distribution of the IL1RN allelic frequencies in Spanish healthy subjects is similar to that previously reported in White subjects. However, the A1 allele is overrepresented in Spanish alcoholics when compared with healthy subjects. No significant differences in allelic frequencies were observed between alcoholics with liver cirrhosis and alcoholics without liver disease or between alcohol-dependent subjects and alcohol abusers. CONCLUSION: The presence of the A1 allele of the IL1RN gene is associated with a higher risk of alcoholism in Spanish men.     

Alcohol suppresses insulin-like growth factor-1 gene expression in prepubertal transgenic female mice overexpressing the bovine growth hormone gene

BACKGROUND: Alcohol (ALC) delays puberty in female rats and alters the development of a normal menstrual pattern in rhesus monkeys. These actions are associated with depressed serum levels of growth hormone (GH), luteinizing hormone and insulin-like growth factor-1 (IGF-1). The mechanism of this ALC-induced depression in IGF-1 is not known, however, could be due to depressed GH and, possibly, to an alteration in the hepatic GH receptor. To assess whether ALC has a direct action at the liver, we used a transgenic mouse model that overexpresses GH, allowing assessment of potential direct actions of ALC on the level of either the GH receptor or the IGF-1-synthesizing machinery within the hepatocyte. METHODS: One group of transgenic mice was fed a liquid diet containing ALC. The second group was pair-fed the companion isocaloric control liquid diet. The third group of transgenic mice was fed Lab Chow and water. The fourth group consisted of normal (nontransgenic) littermates fed Lab Chow and water. Animals received their respective diets for 5 days. Mice were killed during their late juvenile stage of development, and tissues and blood collected and frozen. RESULTS: The ALC-fed transgenic mice showed a decrease (p < 0.01) in hepatic IGF-1a and IGF-1b messenger RNA levels compared with transgenic controls, and this paralleled a decrease (p < 0.01) in serum IGF-1. ALC did not alter the circulating levels of bovine GH held constant by the promotor and did not alter mouse GH receptor protein levels as analyzed by Western blotting. CONCLUSIONS: Using this transgenic animal model that maintains circulating GH in the presence of ALC, we found that the ability of ALC to suppress prepubertal Igf1 gene expression can also occur independently of any alterations in the level of circulating GH. This direct effect on the hepatocyte is a postreceptor event because the GH receptor protein levels were not altered by ALC exposure.     

Mutational analysis of the inhibin alpha gene in preeclamptic women

BACKGROUND: Preeclampsia (PE) is a disorder that occurs in at least 5% of pregnancies and affects both the mother and the unborn baby. A dramatic increase of maternal serum inhibin A concentration in the second and third trimester of pregnancy is a common feature of PE and inhibin A measurement may add significant prognostic information for predicting PE in pregnant women. DESIGN: We evaluated the presence and prevalence of gene polymorphisms for inhibin alpha subunit (INHalpha) in patients affected by PE (no.=50; study group), and in the general population (control group composed of 103 women and 42 men). METHODS: DNA extraction, single strand conformation polymorphism analysis, DNA sequencing, restriction fragment length polymorphism analysis, and Fisher's exact test were used. RESULTS: A 769G-->A transition was found in INHalpha1, but not in INHalpha2 or INHalpha3 fragment. This variant was found in 10/145 normal controls (7,6%), and in 1/50 preeclamptic patients (2%), without significant difference between the two groups (p=0.29). CONCLUSIONS: The prevalence of INHalpha gene variants is not increased in PE. Due to its frequency, the 769G-->A transition may be considered a polymorphism present in the general Italian population.     

Overexpression of the human interleukin 1a gene causes osteopenia in mice

OBJECTIVE: Osteoporosis is a major complication of chronic inflammatory diseases such as rheumatoid arthritis (RA). We describe disordered bone metabolism in transgenic mice that overexpress human interleukin 1a (hIL-1a). METHODS: Bone mineral density (BMD), microcomputed tomography (microCT), histomorphometry, and blood biochemical data of hIL-1a transgenic mice and littermate wild-type mice were examined. RESULTS: The femoral BMD of transgenic mice was decreased by 27.7% compared with wild-type mice. microCT revealed a marked reduction in the trabecular bone, and cortical thinning with an enlarged cavity was observed in femora of transgenic mice. Histomorphometric analysis revealed inhibition of several measures of bone formation, while the serum alkaline phosphatase level was reduced in transgenic mice; however, their indices of bone resorption were not elevated. CONCLUSION: Overexpression of hIL-1a causes osteopenia in mice. It was suggested that the systemic osteopenia in these transgenic mice occurred primarily as a result of decreased bone formation, with a reduction of bone mineralization rather than increased osteoclastic bone resorption. This may be one aspect of bone metabolism in RA that results in disease complications.     

Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan

BACKGROUND AND AIM: Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals. METHODS: A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups. RESULTS: The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066). CONCLUSION: These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.     

Analysis of the CTLA4 gene in Swedish coeliac disease patients

BACKGROUND: A genetic susceptibility to coeliac disease is well established, involving HLA and non-HLA components. CTLA4 is an important regulator of T-cell function and some studies have suggested that sequence variation in the gene might be a determinant of disease susceptibility, although the evidence is conflicting. METHODS: Sixty-two children with biopsy-proven coeliac disease attending a single centre in Sweden were studied. All were genotyped for presence of the HLA-DQA1*0501, B 1*0201 alleles. Those who carried the HLA-DQ heterodimer (58/62) were genotyped for the +49 (A/G) exon I polymorphism. The transmission disequilibrium test (TDT) was used to test for association between coeliac disease and the A allele. The entire CTLA4 gene was screened for other sequence variants using a combination of conformation-sensitive gel electrophoresis and direct sequencing. RESULTS: A significant association between the exon I polymorphism and coeliac disease was observed (P = 0.02). No other sequence variants in CTLA4 were detected. CONCLUSIONS: This study provides further evidence that variation in CTLA4 is a determinant of coeliac disease susceptibility. If not mediated through the +49 (A/G) dimorphism directly, then the effect is likely to be mediated through linkage disequilibrium.     

Cleavage of the ALL1 gene in acute lymphoid leukemia before treatment disappears in relapse.

BACKGROUND AND OBJECTIVE: ALL1 gene rearrangements are frequently found in secondary acute leukemias (ALs). A site-specific cleavage of the ALL1 gene in a consensus sequence for topoisomerase II recognition has been considered to be the initial step leading to ALL1 rearrangement and subsequent therapy-related AL. The aim of the present study was to evaluate this cleavage in our patients, to analyze whether it is a laboratory-produced artefact and to check whether it persists or causes a real ALL1 gene rearrangement at relapse. DESIGN AND METHODS: We studied ALL1 rearrangement in 74 cases of AL before treatment by Southern blot avoiding room temperature exposure or delay in processing the samples which could produce ALL1 cleavage. DNA was available for two cases with ALL1 cleavage; it was analyzed by three different Southern blots in one and two in the other. One case with ALL1 cleavage was also studied in relapse. RESULTS: The presence of the cleavage of the ALL1 DNA was found in 3 of 74 (4%) patients. Two of these three patients had the ALL1 cleavage in three and two different analyses. One case was positive for ALL1 cleavage at diagnosis, but negative for both ALL1 cleavage and ALL1 rearrangement at relapse. INTERPRETATION AND CONCLUSIONS: The fact that a constant pattern was obtained from the same patients in different DNA preparations, supports the notion that ALL1 cleavage is not a laboratory artefact. The absence of the cleavage in a sample from a relapsed patient suggests that the subclone with the ALL1 cleavage, in this case, did not play a clear role in the pathogenesis of disease recurrence.     

A novel mutation of the KAL1 gene in monozygotic twins with Kallmann syndrome

OBJECTIVE: Kallmann syndrome is defined by the association of hypogonadotropic hypogonadism and anosmia. The KAL1 gene is responsible for the X-linked form of Kallmann syndrome. In this study we describe monozygotic twins with Kallmann syndrome due to the same mutation in the KAL1 gene. DESIGN: We studied male monozygotic twins with Kallmann syndrome. METHODS: We analyzed the KAL1 gene using the PCR-direct sequencing method. The twins' mother was examined for the identified mutation. RESULTS: We identified a 14 bp deletion from codon 419 in exon 9 (Pro419del14) in both KAL1 genes of the twins. This was a novel mutation in the KAL1 gene and was responsible for Kallmann syndrome. As Pro419del14 was not detected in the mother of the twins, Pro419del14 was a germline mutation originating from them. These monozygotic twins showed different LH and FSH responses to LH-RH stimulation and different phenotypes such as complications, physiques and psychiatric characters. CONCLUSIONS: We report an identical KAL1 gene mutation in the monozygotic twins with Kallmann syndrome. As these monozygotic twins showed different phenotypes in some respects, we suggest that factors other than mutations in the KAL1gene affect the symptomatic features of Kallmann syndrome.     

Collagen type Ialpha1 gene polymorphism in idiopathic osteoporosis in men

OBJECTIVE: To analyse the distribution of polymorphism of the collagen type Ialpha1 gene (COL1A1) and its relationship with bone metabolism and bone turnover in men with idiopathic osteoporosis. METHODS: A total of 35 male patients with idiopathic osteoporosis, aged 50.4 +/- 10.3 yr, and 60 healthy males (controls), aged 47 +/- 17 yr, were included in the study. Serum osteocalcin, 25-hydroxyvitamin D and parathyroid hormone were determined in all patients. The COL1A1 Sp1 genotypes (SS, SS:, ss) were assessed by restriction enzyme digestion (BAL:1) of DNA amplified by the polymerase chain reaction. RESULTS: Patients with idiopathic osteoporosis had a higher frequency of the s allele than men in the control group (29 vs 11%, P: = 0.003) and a higher frequency of the SS: genotype (patients, 48% SS, 46% SS:, 6% ss; controls, 80% SS, 18% SS:, 2% ss; P: = 0.003). No significant differences between genotypes were observed in serum concentrations of osteocalcin, vitamin D or parathyroid hormone among either the patients or the controls. CONCLUSION: This study suggests that, in men with idiopathic osteoporosis, there is a high prevalence of the s allele and the SS: genotype that is unrelated to other parameters of bone metabolism.     

Role of the progressive ankylosis gene in cartilage mineralization

PURPOSE OF REVIEW: Among the myriad of players in the calcification of cartilage, ANK is a relatively new entrant. It is a multipass transmembrane protein that regulates the transport of inorganic pyrophosphate between the cell and the extracellular space. Mutations in ANK result in two distinct calcification disorders: craniometaphyseal dysplasia and familial calcium pyrophosphate dihydrate deposition disease. The purpose of this review is to highlight recent work on the role of ANK in physiological and pathological calcification of articular and growth plate cartilage. RECENT FINDINGS: New information on the function of ANK suggests that the protein is part of a constellation of critical components that interact to regulate the elaboration of inorganic pyrophosphate. In addition to ANK, these components include alkaline phosphatase, the ectoenzyme PC-1, and osteopontin. ANK expression is also regulated by a variety of growth factors and cytokines that may further affect the transport of inorganic pyrophosphate and may be particularly relevant to the increased levels of expression of ANK in cartilage from chondrocalcinosis and osteoarthritis patients. SUMMARY: Additional studies will be required to understand the contribution of ANK in shaping the fine balance of components necessary for crystal deposition in degenerating articular cartilage. Furthermore, the precise role of inherited mutations in ANK on the elaboration of inorganic pyrophosphate, and the ultimate deposition of either basic calcium phosphate or calcium pyrophosphate dihydrate crystals, remains unclear.