Fehringer P

References (7)

Title : Transcriptional regulation of lysosomal acid lipase in differentiating monocytes is mediated by transcription factors Sp1 and AP-2 - Ries_1998_J.Lipid.Res_39_2125
Author(s) : Ries S , Buchler C , Langmann T , Fehringer P , Aslanidis C , Schmitz G
Ref : J Lipid Res , 39 :2125 , 1998
Abstract : Human lysosomal acid lipase (LAL) is a hydrolase required for the cleavage of cholesteryl esters and triglycerides derived from plasma lipoproteins. It is shown here that during monocyte to macrophage differentiation, the expression of LAL-mRNA is induced. This induction is dependent on protein kinase C activity and protein synthesis. The cell type-specific increase in LAL expression is further investigated in the THP-1 cell line with respect to transcriptional regulation. The human monocytic leukemia cell line THP-1 differentiates into macrophage-like cells when treated with phorbol esters. In order to determine the cis-acting elements necessary for both basal and phorbol 12-myristate-13 acetate (PMA)-enhanced promoter activity, we performed deletion analysis and reporter gene assays. A PMA responsive element has been identified between -182 bp and -107 bp upstream of the major transcription start site. Gel mobility shift assays demonstrated that binding of Sp1 and AP-2 to the LAL promoter is increased by PMA in THP-1 cells. Co-transfections with expression plasmids for Sp1 and AP-2 further emphasized the important role of these transcription factors in both basal and PMA-enhanced LAL expression. Our data suggest that differentiation dependent increase of lysosomal acid lipase (LAL) expression in THP-1 cells is mediated by a concerted action of Sp1 and AP-2.
ESTHER : Ries_1998_J.Lipid.Res_39_2125
PubMedSearch : Ries_1998_J.Lipid.Res_39_2125
PubMedID: 9799798
Gene_locus related to this paper: human-LIPA

Title : Different missense mutations in histidine-108 of lysosomal acid lipase cause cholesteryl ester storage disease in unrelated compound heterozygous and hemizygous individuals - Ries_1998_Hum.Mutat_12_44
Author(s) : Ries S , Buchler C , Schindler G , Aslanidis C , Ameis D , Gasche C , Jung N , Schambach A , Fehringer P , Vanier MT , Belli DC , Greten H , Schmitz G
Ref : Hum Mutat , 12 :44 , 1998
Abstract : Cholesteryl ester storage disease (CESD) and Wolman disease (WD) are both autosomal recessive disorders associated with reduced activity of lysosomal acid lipase (LAL), that leads to the tissue accumulation of cholesteryl esters in endosomes and lysosomes. WD is caused by genetic defects of LAL that leave no residual enzymatic activity, while in CESD patients a residual LAL activity can be identified. We have analyzed the LAL cDNA in three CESD patients from two nonrelated families and identified the mutations responsible for the disease. The associated genetic defects characterized revealed compound heterozygosity for a splice defect leading to skipping of exon 8, due to a G-->A transition at position -1 of the exon 8 splice donor site, and a point mutation leading to a Hisl08Pro change (CAT-->CCT) in two patients (siblings) with mild CESD phenotype. A further CESD patient was hemizygous for a His108-->Arg missense mutation (CAT-->CGT) in combination with a partial deletion of the LAL gene and was affected more severely. Expression of the LAL enzymes with the His108-->Pro and His108-->Arg mutation in insect cells revealed residual enzymatic activities of 4.6% versus 2.7%, respectively, compared with controls. Therefore, His108 seems to play a crucial role in folding or catalytic activity of the lysosomal acid lipase. This is the first description of two different, naturally occurring mutations involving the same amino acid residue in the lysosomal acid lipase in unrelated CESD patients. Moreover, our results demonstrate that the variable manifestation of CESD can be explained by mutation-dependent, variable inactivation of the LAL enzyme.
ESTHER : Ries_1998_Hum.Mutat_12_44
PubMedSearch : Ries_1998_Hum.Mutat_12_44
PubMedID: 9633819
Gene_locus related to this paper: human-LIPA

Title : Altered mononuclear phagocyte differentiation associated with genetic defects of the lysosomal acid lipase - Rothe_1997_Atherosclerosis_130_215
Author(s) : Rothe G , Stohr J , Fehringer P , Gasche C , Schmitz G
Ref : Atherosclerosis , 130 :215 , 1997
Abstract : Multiparameter flow cytometry reveals a complex heterogeneity of mononuclear phagocyte differentiation within the peripheral blood compartment. In this study, the relation of abnormal cellular lipid metabolism to the phenotype of peripheral blood mononuclear phagocytes, which finally may be related to atherogenesis, was analyzed using recently characterized autosomal recessive defects of lysosomal acid lipase (LAL) expression as model system. The reduction of LAL activity in nine heterozygote, disease free carriers of mutations from two cholesteryl ester storage disease (CESD) pedigrees and the family of a patient with Wolman disease was associated with an increased fraction of monocytes which expressed CD56 (N-CAM) (4.1 +/- 2.7% of monocytes, compared to 2.2 +/- 0.5% in ten controls, P < 0.05), an antigen characteristic of immature myeloid cells, suggesting an increased turnover of monocytes. Furthermore, a trend was observed towards an enhanced blood pool of more mature mononuclear phagocytes which show decreased expression of the 55 kD lipopolysaccharide receptor (CD14) together with either expression of the Fc-gamma-receptor III (CD16) or a high expression of CD33. A similar phenotype of peripheral mononuclear phagocytes was observed in the two CESD patients analyzed. In conclusion, our data suggest that these monogenetic defects of lysosomal lipoprotein metabolism are associated with complex alterations of mononuclear phagocyte differentiation and extravasation.
ESTHER : Rothe_1997_Atherosclerosis_130_215
PubMedSearch : Rothe_1997_Atherosclerosis_130_215
PubMedID: 9126667
Gene_locus related to this paper: human-LIPA

Title : A new mutation in the gene for lysosomal acid lipase leads to Wolman disease in an African kindred - Ries_1996_J.Lipid.Res_37_1761
Author(s) : Ries S , Aslanidis C , Fehringer P , Carel JC , Gendrel D , Schmitz G
Ref : J Lipid Res , 37 :1761 , 1996
Abstract : Cholesteryl ester storage disease (CESD) and Wolman disease (WD) are both autosomal recessive disorders associated with reduced activity and genetic defects of lysosomal acid lipase (LAL). The strikingly more severe course of WD is caused by genetic defects of LAL that leave no residual enzymatic activity. Mutations at the exon 8/intron 8 transition of the LAL gene have been identified in several CESD and WD patients and are responsible for the manifestation of the disease. We have determined the genetic defect in a 3-month-old boy of African origin affected by WD. No enzymatic activity of the lysosomal acid lipase was detectable in white blood cells and cultured fibroblasts. Analysis of his LAL cDNA and genomic DNA revealed that he was homozygous for a mutation at position -3 of the exon 8 splice donor site. A C-->T transition leads to a nonsense codon and to a premature termination of the LAL protein at amino acid 277. Due to this mutation, a shorter LAL mRNA species was also generated that lacked exon 8 and was deficient of the nonsense codon. As a consequence, the protein synthesis proceeded to the natural termination codon, but the enzyme generated had an internal deletion of 24 amino acids (254-277) and was also inactive. These findings, together with our previous observations when analyzing the mutations in WD and CESD patients lead to the conclusion that the more severe WD is due to mutations that absolutely abolish lysosomal acid lipase (LAL) enzyme activity and the cholesteryl ester storage disease phenotype is due to mutations that allow some residual LAL activity to be manifested.
ESTHER : Ries_1996_J.Lipid.Res_37_1761
PubMedSearch : Ries_1996_J.Lipid.Res_37_1761
PubMedID: 8864960
Gene_locus related to this paper: human-LIPA

Title : Genetic and biochemical evidence that CESD and Wolman disease are distinguished by residual lysosomal acid lipase activity - Aslanidis_1996_Genomics_33_85
Author(s) : Aslanidis C , Ries S , Fehringer P , Buchler C , Klima H , Schmitz G
Ref : Genomics , 33 :85 , 1996
Abstract : Cholesteryl ester storage disease (CESD) and Wolman disease are both autosomal recessive disorders associated with reduced activity and genetic defects of lysosomal acid lipase (LAL). We provide evidence that the strikingly more severe course of Wolman disease is caused by genetic defects of LAL that leave no residual enzyme activity. In a CESD patient, a G --> A mutation at position -1 of the exon 8 splice donor site results in skipping of exon 8 in 97% of the LAL hnRNA originating from this allele, while 3% are spliced correctly, resulting in full-length LAL enzyme. The mutant LAL mRNA codes for a protein lacking amino acids 254 to 277. On the other allele, a G --> T mutation leads to a premature stop codon at Gly245, resulting in inactive LAL enzyme. In addition, the previously identified Leu179 --> Pro mutation is present on this allele, and the LAL mRNA is rendered unstable by the premature stop codon. Analysis of two children with Wolman disease showed that both were homozygous for a G --> A mutation at position +1 of the same splice donor site as for the CESD patient, leading to skipping of exon 8. In contrast to the CESD patient, no correctly spliced mRNA was detectable. We have also expressed a wildtype LAL cDNA and the mutant LAL cDNA from one Wolman patient in Sf9 and H5 insect cells. We demonstrate that the LAL enzyme generated from the wildtype LAL cDNA was active in homogenates from Sf9 and H5 cells, while the enzyme with the internal deletion of 24 amino acids originating from the LAL cDNA of the Wolman patient was not. The combined data provide evidence that the only functionally relevant genetic difference between the Wolman patients and the CESD patient is that the splice defect in Wolman, which affects one of the invariable nucleotides of the splice consensus sequences (position +1), does not permit any correct splicing, whereas the defect observed in CESD (position -1) allows some correct splicing (3% of total LAL mRNA) and therefore the synthesis of functional enzyme.
ESTHER : Aslanidis_1996_Genomics_33_85
PubMedSearch : Aslanidis_1996_Genomics_33_85
PubMedID: 8617513
Gene_locus related to this paper: human-LIPA

Title : Purification, cloning, and expression of a human enzyme with acyl coenzyme A: cholesterol acyltransferase activity, which is identical to liver carboxylesterase - Becker_1994_Arterioscler.Thromb_14_1346
Author(s) : Becker A , Bottcher A , Lackner KJ , Fehringer P , Notka F , Aslanidis C , Schmitz G
Ref : Arterioscler Thromb , 14 :1346 , 1994
Abstract : An enzyme with acyl coenzyme A:cholesterol acyltransferase (ACAT) activity was isolated from porcine liver, and sequences derived from trypsinized peptides indicated homology to liver carboxylesterase. By use of degenerate primers, human cDNA clones were identified, which were identical to human liver carboxylesterase. Expression of the full-length cDNA in Chinese hamster ovary (CHO) cells led to an approximately threefold increase in cellular ACAT activity. This was accompanied by an approximately 20-fold increase of cellular cholesteryl ester content. By light and electron microscopy, recombinant CHO cells contained numerous lipid droplets that were not present in control CHO cells. Expression of an antisense cDNA in HepG2 cells reduced cellular ACAT activity by 35% compared with control. To further investigate the role of the enzyme in cellular cholesterol homeostasis, regulation of the mRNA was investigated in 7-day cultured human mononuclear phagocytes (MNPs). When these cells were incubated in lipoprotein-deficient serum for 18 hours, the mRNA for ACAT/carboxylesterase was almost not detectable on Northern blots, whereas after incubation with acetylated low-density lipoproteins, a strong hybridization signal was obtained. This is evidence that the mRNA of ACAT/carboxylesterase is induced by cholesterol loading. It is concluded from the data presented that ACAT/carboxylesterase is relevant for cellular cholesterol esterification in vivo. The regulation in MNPs indicates that the enzyme is also involved in foam cell formation during early atherogenesis.
ESTHER : Becker_1994_Arterioscler.Thromb_14_1346
PubMedSearch : Becker_1994_Arterioscler.Thromb_14_1346
PubMedID: 8049197
Gene_locus related to this paper: human-CES1 , pig-EST1

Title : A splice junction mutation causes deletion of a 72-base exon from the mRNA for lysosomal acid lipase in a patient with cholesteryl ester storage disease - Klima_1993_J.Clin.Invest_92_2713
Author(s) : Klima H , Ullrich K , Aslanidis C , Fehringer P , Lackner KJ , Schmitz G
Ref : J Clinical Investigation , 92 :2713 , 1993
Abstract : The genetic defect leading to cholesteryl ester storage disease (CESD) has been determined in a 12-yr-old patient. Lysosomal acid lipase (LAL) activity in cultured skin fibroblasts was reduced to approximately 9% of control fibroblasts. Plasma cholesterol (255 mg/dl) and LDL-cholesterol (215 mg/dl) were elevated whereas HDL-cholesterol was reduced (19 mg/dl). Triglycerides were moderately elevated (141 mg/dl). There were no clinical abnormalities with the exception of hepatosplenomegaly. Both parents have reduced LAL activity in white blood cells. PCR analysis of the LAL mRNA from the propositus revealed a single slightly smaller mRNA species in skin fibroblasts as well as in leukocytes. The mother of the patient and his older brother had two mRNA species: one of normal size and one of the same size as the propositus. The father has a LAL mRNA of normal size only. Sequence analysis of a PCR-amplified cDNA fragment showed a 72-bp in-frame deletion resulting in the loss of the codons for amino acids 254-277. Analysis of genomic DNA revealed that the 72 bp represent an exon, indicating that the deletion in the mRNA is caused by defective splicing. Sequence analysis of the patient's genomic DNA revealed a G-->A substitution in the last nucleotide of the 72-bp exon in one of his alleles. The mutant allele was shown to cosegregate with the truncated mRNA in the pedigree, providing further evidence that the G-->A substitution causes aberrant splicing and exon skipping. No normal-sized mRNA is detectable in the propositus even though he is not homozygous for the splice site mutation. This can be only accounted for by assuming that he is a compound heterozygote with a null allele inherited from his father. In summary, the data presented provide evidence that deletion of the codons for amino acids 254-277 in the LAL mRNA in combination with a null allele cause the clinical expression of CESD in our patient.
ESTHER : Klima_1993_J.Clin.Invest_92_2713
PubMedSearch : Klima_1993_J.Clin.Invest_92_2713
PubMedID: 8254026
Gene_locus related to this paper: human-LIPA