Regina Haas

Intravenous administration of recombinant adenoviruses causes thrombocytopenia, anemia and erythroblastosis in rabbits

Recombinant adenoviruses are highly efficient gene transfer vehicles but their administration to mammals is accompanied by a strong inflammatory response. The present study reports additional side effects observed during adenoviral gene transfer studies in rabbits.

Apolipoprotein A-I induced amyloidosis

Amyloidosis is characterized by extracellular deposits of protein fibrils with a high content of β‐sheets in secondary structure. The protein forms together with proteoglycans amyloid fibrils causing organ damage and serious morbidity. Intact apolipoprotein A‐I (apoA‐I) is an important protein in lipid metabolism regulating the synthesis and catabolism of high density lipoproteins (HDL). Usually, apoA‐I is not associated with amyloidosis. However, four naturally occuring mutant forms of apoA‐I are known so far resulting in amyloidosis. The most important feature of all variants is the very similar formation of N‐terminal fragments which were found in the amyloid deposits (residues 1–83 to 1–94). The new insights in the understanding of the association of apoA‐I with HDL, its metabolism, and its hypothesized structural findings may explain a common mechanism for the genesis of apoA‐I induced amyloidosis. Here we summarized the specific features of all known amyloidogenic variants of apoA‐I and speculate about its metabolic pathway, which may have general implications for the metabolism of apoA‐I.

Mutation analysis in 46 German families with familial hypercholesterolemia: Identification of 8 new mutations

In order to obtain a survey of the mutations being prevalent in Northern Germany and to enable molecular genetic testing for families with clinically diagnosed familial hypercholesterolemia (FH), we screened 46 unrelated German individuals with elevated LDL levels for mutations in the 18 exons and their flanking intron sequences including the promotor region of the LDL receptor (LDLR) gene. In addition, we tested all patients for the presence of mutations in the gene coding for apolipoprotein B‐100 (apoB‐100). We detected 15 mutations affecting the LDLR gene, 8 of which, designated A29S, 195insAT, 313+1insG, 553insG, 680insGGACAAATCTG, D200N, E267K and L411V have not yet been reported. One patient is heterozygous for the double mutant N543H and 2393del9Bp. Two patients carried the mutation R3500Q (Arg→Glu) within the apoB‐100 gene.

In vivo kinetics as a sensitive method for testing physiologically intact human recombinant apolipoprotein A-I: comparison of three different expression systems

In order to assess the structural and functional integrity of recombinant human apoA-I, we expressed apoA-I using three different expression systems: Baculovirus transfected Spodoptera frugiperda (Sf9) cells, stably transfected Chinese hamster ovary (CHO) cells, and transformed Escherichia coli (E. coli). Purified apoA-I from the three expression systems was radioiodinated and their catabolism was compared in normolipemic rabbits. The kinetic turnover studies of radiolabelled apoA-I in normolipemic rabbits revealed that highly purified recombinant apoA-I had an identical decay curve compared to native apoA-I, regardless whether it was purified from Sf9 cells, CHO cells, or E. coli. We also determined the association of the three recombinant apoA-I forms with both rabbit and human HDL. All three recombinant apoA-I forms were associated with HDL2 and HDL3 after injection into the rabbits and after incubation with human serum using both a Superose 6 column separation system and density gradient ultracentrifugation. The addition of the pro-segment or the addition of methionine at the amino-terminal end of apoA-I did not alter its metabolism and association to HDL. In conclusion, all studied expression systems are capable of producing high levels of physiologically intact recombinant human apoA-I. The aminoterminal addition of the prosegment of apoA-I or methionine did not alter the in vivo metabolism of apoA-I or its association to HDL.

Mutation analysis in patients with Wilson disease: Identification of 4 novel mutations

In order to obtain novel mutations in the recently discovered Wilson disease gene, we screened 5 unrelated German individuals for mutations in the 21 exons and their flanking intronic sequences. We detected 9 mutations affecting the Wilson disease gene. Four of those, designated 802‐808delTGTAAGT, 2008‐2013delTATATG, Cys985Thr, and Ile1148Thr have not yet been reported. One patient had a homozygous mutation whereas the remaining four subjects were compound heterozygous. Therefore these data confirm, that mutations causing Wilson disease are frequently found in affected subjects and they are very heterogenous. Hum Mutat 14:88, 1999.

Mutation analysis in 46 German families with familial hypercholesterolemia: identification of 8 new mutations. Mutations in brief no. 226. Online.

In order to obtain a survey of the mutations being prevalent in Northern Germany and to enable molecular genetic testing for families with clinically diagnosed familial hypercholesterolemia (FH), we screened 46 unrelated German individuals with elevated LDL levels for mutations in the 18 exons and their flanking intron sequences including the promotor region of the LDL receptor (LDLR) gene. In addition, we tested all patients for the presence of mutations in the gene coding for apolipoprotein B-100 (apoB-100). We detected 15 mutations affecting the LDLR gene, 8 of which, designated A29S, 195insAT, 313+1insG, 553insG, 680insGGACAAATCTG, D200N, E267K and L411V have not yet been reported. One patient is heterozygous for the double mutant N543H and 2393del9Bp. Two patients carried the mutation R3500Q (Arg-->Glu) within the apoB-100 gene.The diagnosis of Peutz‐Jeghers syndrome is based on the occurrence of hamartomatous gastrointestinal polyps and perioral pigment spots. In view of the development of hamartomatous polyps in several syndromes and the variability of pigment spots in Peutz‐Jeghers patients, identification of affected individuals is difficult. Recently, germline mutations in the STK11 gene have been reported as a molecular cause of Peutz‐Jeghers syndrome. We present four novel inactivating mutations identified by direct sequencing of all 9 exons of the STK11 gene in 4 patients suggestive of Peutz‐Jeghers syndrome: three frameshift mutations (125‐137del; 474‐480del; 516‐517insT) and one nonsense mutation (Q220X). Our data obtained in these patients and in those reported previously emphasize the diagnostic value of histological discrimination between different types of hamartomatous polyps and of molecular analysis, particularly in cases with no family history of the disease.

Mutation analysis in patients with Wilson disease: identification of 4 novel mutations. Mutation in brief no. 250. Online.

In order to obtain novel mutations in the recently discovered Wilson disease gene, we screened 5 unrelated German individuals for mutations in the 21 exons and their flanking intronic sequences. We detected 9 mutations affecting the Wilson disease gene. Four of those, designated 802‐808delTGTAAGT, 2008‐2013delTATATG, Cys985Thr, and Ile1148Thr have not yet been reported. One patient had a homozygous mutation whereas the remaining four subjects were compound heterozygous. Therefore these data confirm, that mutations causing Wilson disease are frequently found in affected subjects and they are very heterogenous. Hum Mutat 14:88, 1999.