Enzyme Replacement Therapy in the Treatment of Fabry Disease / 罕见病研究

Fabry disease is an X-linked inherited lysosomal storage disease caused by the mutation of GLA gene that encodes α-galactosidase A (α-Gal A). GLA gene mutation causes the decline or deficiency in the activity of α-Gal A, leading to the accumulation of its substrates in the lysosomes of multiple organs and tissue that causes systemic damage and threatens the life of patients. Enzyme replacement therapy (ERT) is the standard of care for Fabry disease. ERT slows or prevents the progression of organ damage, effectively improving heart, brain, kidney functions and significantly improves quality of life. At present, there are two main ERT drugs, agalsidase alpha and agalsidase beta, which have the same amino acid sequence and different N-terminal sugars, and are used for the treatment of Fabry disease. In this paper, the efficacy and safety of ERT in the treatment of Fabry disease were summarized by reviewing the relevant literature at home and abroad and combining the results of some cases treated in Department of Nephrology, Provincial Hospital affiliated to Shandong First Medical University. Previous literature has shown that enzyme replacement therapy is the most important specific treatment for Fabry disease, which has a protective effect on important organs such as kidney, heart, and nervous system.

Expression, purification and functional verification of recombinant human α-galactosidase A in suspension CHO-S / 中国药理学通报

Aim To express and purify rhα-Gal A with a 6 X His tag via using a serum-free expression system in high-density suspension culture of Chinese hamster ovary cells ( CHO-S) , and to verify the scavenging effect of rhα-Gal A on globular trisaccharide ceramide (Gb3 or GL3) . Methods The construction of recombinant protein expression vector, pcDNA4-GLA, was achieved by fusing the human α-galactosidase cDNA, gla, with 6 X His tag and artificial DNA synthesis. The expression plasmid was transfected into the suspended CHO-S to express rhα-Gal A and then purified. Following this procedure, we determined rhα-Gal A's expression, the enzymatic activity, and the glycosylation of the recombinant enzyme. Co-incubation with cultured cells was performed to examine whether rhα-Gal A could be taken up into the cells and effectively remove Gb3 substrates. Results rhα-Gal A was successfully expressed and purified after transiently transfecting pcDNA4-GLA into the suspended CHO-S, and the yield was up to (100 ±20. 6) mg • L

Clinical significance of α-galactosidase A activity assay in the screening and diagnosis of Febry disease / 中华内分泌代谢杂志

α-Galactosidase A (α-Gal A ) activities in plasma and peripheral blood granulocytes of 100healthy subjects and one patient with Fabry disease was determined by means of fluorogenic substrate.The results showed that the enzymatic activities of peripheral blood granulocytes and plasma in 100 subjects were (51.97 ± 15.24)and(148.08±26.30) nmol · h-1 · ml-1 respectively.The α-Gal A activities in plasma and granulocytes were positively correlated( r=0.533,P＜0.01 ).The enzymatic activities in peripheral blood granulocytes and plasma of the patients with Fabry disease were 1.05 and 10.06 nmol · h-1 · ml-1 respectively,both much lower than those of 100healthy subjects.These results suggest that α-Gal A activity in plasma and peripheral blood granulocytes can be used for diagnosis and screening of Fabry disease.

Gene mutation and enzymatic activity analysis of α-galactosidase A in a patient with Fabry disease / 中华内分泌代谢杂志

Objective To analyse the clinical characteristics,gene mutation and enzymatic activity of αgalactosidase A(α-GalA)in a 15-year-old male patient with typical Fabry disease,whose mother was without any clinical manifestations.Methods Clinical features and laboratory data were collected from the patient and his mother.Genomie DNA was extracted from peripheral blood of the patient.his mother,and a healthy control subject.Seven exons of the GLA gene were amplified by PCR.PCR products were purified.cloned into T vector,and then sequenced.The enzymatic activity of α-GalA Was measured by fluorimetrie substrate assay. Results DNA sequencing results showed that a missense mutation of 10036-10038delAAG in exon 7 WaS identified in the patient,resulting in the replacement of 374 lysine and 375 glyeine by arginine,which Was not previously reported.The patient Was a hemizygote with gene mutation,his mother WaS a heterozygote carrying gene mutation,and the healthy control without mutation.α-GalA enzymatic activity assay showed that the enzymatic activity of the patient with GLA gene mutation was only 50%of the healthy control subject,while the enzymatic activity of the patient's mother Was about 70%of the heahhy control SObject.Conclusiolls Detecting GLA gene mutation and α-GalA enzymatic activity in patients with Fabry disease who have been clinically diagnosed seelns to be helpful in finding other patients in the family and in further understanding the molecular pathogenesis of that disease.