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At least 523 records · Page 29Linked to original sources
PubMed2003

Clinical trial of oral artesunate with or without high-dose primaquine for the treatment of vivax malaria in Thailand.

We studied prospectively 801 Thai patients admitted to the Bangkok Hospital for Tropical Diseases with acute, symptomatic Plasmodium vivax malaria to determine the optimum duration of treatment with oral artesunate and the safety, tolerability, and effectiveness of a high dose of primaquine in prevention of relapse. Patients were randomly assigned to one of four treatment groups: 1) a five-day course of artesunate (Group A5); 2) a seven-day course of artesunate (Group A7); 3) a five-day course of artesunate plus a 14-day course of high-dose primaquine (0.6 mg/kg, maximum dose = 30 mg) (Group A5 + P); and 4) a seven-day course of artesunate plus a 14-day course of high-dose primaquine (Group A7 + P). During 28 days of observation, P. vivax reappeared in the blood of 50% of those who received artesunate alone (Groups A5 and A7), compared with none of those who received primaquine (Groups A5 + P and A7 + P; P < 0.0001). Adverse effects were confined to the 13 patients with a deficiency for glucose-6-phosphate dehydrogenase; high-dose primaquine (0.6 mg/kg of base a day) had to be stopped in four (31%) patients because of a significant decrease in the hematocrit. The combination of five days of artesunate and 14 days of primaquine is a highly effective and generally well-tolerated treatment regimen for vivax malaria in Thailand.

Administration, Oral↗
PubMed2026

MYDGF as a telomerase activator and therapeutic target for osteoarthritis.

Osteoarthritis (OA) involves progressive cartilage breakdown. This is driven by impaired chondrocyte function and an imbalance in the extracellular matrix homeostasis. However, the key upstream regulators that maintain healthy chondrocytes are still not fully known. Here, we report that myeloid-derived growth factor (MYDGF) is a novel regulator of telomerase activity and is critical for cartilage health. Using a genome-wide CRISPR-Cas9 screen with a TERT reporter system, MYDGF was identified as a strong positive regulator of telomerase. Functional studies confirmed that MYDGF positively regulates TERT expression and telomerase activity in both HeLa and ATDC5 cells. In a mouse surgical destabilization of the medial meniscus (DMM) OA model, MYDGF knockout (KO) mice exhibited more severe cartilage damage. Conversely, delivering MYDGF into the knee joint using AAV virus partially alleviated cartilage injury. Transcriptome profiling revealed that MYDGF-deficient chondrocytes exhibit downregulated key pathways involved in matrix building and upregulated inflammatory signals, indicating a shift in cell state. In summary, our work establishes MYDGF as a key upstream factor for both telomerase and cartilage matrix homeostasis remodeling. It connects telomerase function to chondrocyte health. These findings also highlight MYDGF as a promising new target for treating osteoarthritis.

Cartilage degeneration↗
PubMed1999

Insertion of sequences into the 3' untranslated region of a replication-competent spleen necrosis virus vector disrupts env gene expression.

The genomes of all replication-competent retroviruses contain cis-acting elements that regulate gene expression. However, the identities of many of these elements remain to be characterized. Inserting sequences into the 3' untranslated region of a replication-competent spleen necrosis virus (SNV) vector disrupted its ability to replicate. Inserts varying in sequences and sizes (0.4-kb to 1.6-kb) all resulted in this defect. Genetic compensation experiments and immunostaining revealed that env gene expression was deficient. Northern analysis indicated the presence of spliced viral mRNA of the correct size although at a reduced level compared to a wildtype vector. It is likely that the block in env expression occurs at a post-transcriptional step. These results suggest that the function of a cis-acting element distinct from the constitutive transport element is disrupted by the inserted sequences into the 3' untranslated region of SNV.

3' Untranslated Regions↗
PubMed1993

Isolation and characterization of a human ileocecal carcinoma cell line (HCT-8) subclone resistant to fluorodeoxyuridine.

A 5-fluoro-2'-deoxyuridine (FdUrd)-resistant subclone (Fd9XR) of HCT-8 (human ileocecal carcinoma) cells was established by two schedules of drug exposure. Initially, cells were exposed to short-term (3 hr) 100 nM FdUrd repeatedly (9 cycles over 8 months), and cells were then exposed to 10 nM FdUrd continuously. During this latter stage, a colony (Fd9XR) with fast growth rate was isolated, expanded, and characterized with respect to mechanisms of resistance to FdUrd and cross-resistance to other chemotherapeutic agents. Fd9XR cells were 1000-fold resistant to FdURD, but 3-fold more sensitive to 5-fluorouracil (FUra) than HCT-8 cells. After a 3-hr treatment with FdUrd, Fd9XR cells accumulated 6630-, 69-, and 3.7-fold less fluorodeoxyuridylate (FdUMP), fluorouridine triphosphate (FUTP) and acid-insoluble materials, respectively, than HCT-8 cells. However, when FUra was substituted for FdUrd, Fd9XR cells accumulated 9.2-, 3.1-, and 2.3-fold more FdUMP, FUTP and acid-insoluble materials, respectively, than HCT-8 cells. Fd9XR and HCT-8 were similar in their growth rates, combined pools of 5,10-methylenetetrahydrofolates (5,10-CH2H4PteGlun) and tetrahydrofolates (H4PTeGlun), thymidine phosphorylase (TP) activity, and level and activity of thymidylate synthase (TS). In contrast, thymidine kinase (TK) activity of Fd9XR was 0.23 and 0.35% of that of HCT-8, for thymidine (dThd) and FdUrd as substrates, respectively. Furthermore, Fd9XR cells exhibited greater sensitivity to the antifolate TS inhibitor ICI D1694 and to methotrexate (MTX) than HCT-8 cells. In addition, dThd alone and in combination with hypoxanthine did not offer any protection against the cytotoxic effect of ICI D1694 in Fd9XR cells. These results indicate that in Fd9XR cells (1) TK deficiency is the primary mechanism of resistance to FdUrd; (2) the greater sensitivity to FUra was associated with higher pools of FdUMP and FUTP with a subsequently higher level of incorporation into cellular RNA; and (3) antifolate compounds, e.g. ICI D1694 and MTX, could be useful agents in the treatment of FdUrd-resistant tumors associated with decreased TK activity and decreased capacity of utilizing dThd.

Antimetabolites, Antineoplastic↗
PubMed2005

Defective NKT cell development in mice and humans lacking the adapter SAP, the X-linked lymphoproliferative syndrome gene product.

SAP is an adaptor protein expressed in T cells and natural killer cells. It plays a critical role in immunity, as it is mutated in humans with X-linked lymphoproliferative syndrome (XLP), a fatal immunodeficiency characterized by an abnormal response to Epstein-Barr virus (EBV) infection. SAP interacts with the SLAM family receptors and promotes transduction signal events by these receptors through its capacity to recruit and activate the Src kinase FynT. Because it has been previously established that FynT is selectively required for the development of NKT cells, we examined NKT cells in SAP-deficient mice and in humans with XLP. In the absence of SAP, the development of NKT cells is severely impaired both in mice and in humans. These results imply that SAP is a potent regulator of NKT cell development. They also identify for the first time a defect in NKT cells associated with a human primary immunodeficiency, revealing a potential role of NKT cells in the immune response to EBV.

Animals↗
PubMed2005

Somatic induction of Pten loss in a preclinical astrocytoma model reveals major roles in disease progression and avenues for target discovery and validation.

High-grade astrocytomas are invariably deadly and minimally responsive to therapy. Pten is frequently mutated in aggressive astrocytoma but not in low-grade astrocytoma. However, the Pten astrocytoma suppression mechanisms are unknown. Here we introduced conditional null alleles of Pten (Pten(loxp/loxp)) into a genetically engineered mouse astrocytoma model [TgG(deltaZ)T121] in which the pRb family proteins are inactivated specifically in astrocytes. Pten inactivation was induced by localized somatic retroviral (MSCV)-Cre delivery. Depletion of Pten function in adult astrocytoma cells alleviated the apoptosis evoked by pRb family protein inactivation and also induced tumor cell invasion. In primary astrocytes derived from TgG(deltaZ)T121; Pten(loxp/loxp) mice, Pten deficiency resulted in a marked increase in cell invasiveness that was suppressed by inhibitors of protein kinase C (PKC) or of PKC-zeta, specifically. Finally, focal induction of Pten deficiency in vivo promoted angiogenesis in affected brains. Thus, we show that Pten deficiency in pRb-deficient astrocytoma cells contributes to tumor progression via multiple mechanisms, including suppression of apoptosis, increased cell invasion, and angiogenesis, all of which are hallmarks of high-grade astrocytoma. These studies not only provide mechanistic insight into the role of Pten in astrocytoma suppression but also describe a valuable animal model for preclinical testing that is coupled with a primary cell-based system for target discovery and drug screening.

Alleles↗
PubMed2000

NADPH oxidase-derived free radicals are key oxidants in alcohol-induced liver disease.

In North America, liver disease due to alcohol consumption is an important cause of death in adults, although its pathogenesis remains obscure. Despite the fact that resident hepatic macrophages are known to contribute to early alcohol-induced liver injury via oxidative stress, the exact source of free radicals has remained a mystery. To test the hypothesis that NADPH oxidase is the major source of oxidants due to ethanol, we used p47(phox) knockout mice, which lack a critical subunit of this major source of reactive oxygen species in activated phagocytes. Mice were treated with ethanol chronically, using a Tsukamoto-French protocol, for 4 weeks. In wild-type mice, ethanol caused severe liver injury via a mechanism involving gut-derived endotoxin, CD14 receptor, production of electron spin resonance-detectable free radicals, activation of the transcription factor NF-kappaB, and release of cytotoxic TNF-alpha from activated Kupffer cells. In NADPH oxidase-deficient mice, neither an increase in free radical production, activation of NF-kappaB, an increase in TNF-alpha mRNA, nor liver pathology was observed. These data strongly support the hypothesis that free radicals from NADPH oxidase in hepatic Kupffer cells play a predominant role in the pathogenesis of early alcohol-induced hepatitis by activating NF-kappaB, which activates production of cytotoxic TNF-alpha.

Alcohol Drinking↗
PubMed1998

Rapid molecular diagnosis of erythropoietic protoporphyria among Swiss patients.

Erythropoietic protoporphyria (EPP) is an autosomal dominant inherited disorder with incomplete penetrance. It is caused by partial deficiency of ferrochelatase, the last enzyme in the heme biosynthetic pathway. Measurement of protoporphyrin concentrations in red cells and feces, although sufficient for diagnosis of symptomatic EPP patients, fails to detect asymptomatic gene carriers. We have developed a molecular diagnostic procedure for rapid and reliable screening of five known mutations in the ferrochelatase gene among Swiss EPP patients in a single denaturing gradient gel electrophoresis (DGGE) gel.

Electrophoresis, Polyacrylamide Gel↗
PubMed1997

[Determination of rate order for degradation of drugs with nonisothermal stability experiment].

By a theoretical investigation of simulated nonisothermal data, the inability to determine the rate order for degradation of drugs with ordinary nonisothermal experiment was discussed. Results indicate that both rate order n and activation energy E can change the curvature of the c-t curve and the change caused by higher n can be compensated by higher E in ordinary nonisothermal experiments. That means a suitable E can always be assessed to fit each of the definite n (0, 1, or 2 in our study) very well. As a result, a same set of c-t data can be well fitted by different combinations of n and E. This is why the rate order cannot be assessed in ordinary nonisothermal experiments. To overcome this deficiency, it is important that there have both temperature rising and lowering parts in one nonisothermal experiment. A new heating model, temperature rising and lowering program, was presented. With this new heating model, the kinetic parameters, including the rate order, can be obtained in one nonisothermal stability experiment. The ability of the new heating model to determine rate order is almost the same as that of isothermal experiments.

Drug Stability↗
PubMed2002

Bid-mediated mitochondrial pathway is critical to ischemic neuronal apoptosis and focal cerebral ischemia.

We have investigated the role of the BH3-only pro-death Bcl-2 family protein, Bid, in ischemic neuronal death in a murine focal cerebral ischemia model. Wild-type and bid-deficient mice of inbred C57BL/6 background were subjected to 90-min ischemia induced by left middle cerebral artery occlusion followed by 72-h reperfusion. The volume of ischemic infarct was significantly smaller in the bid-deficient brains than in the wild-type brains, suggesting that Bid participated in the ischemic neuronal death. Indeed, following the ischemic treatment there was a significant reduction of apoptosis in the ischemic areas, particularly in the inner infarct border zone (the penumbra), of the bid-deficient brains. In addition, activation of Bid in the wild-type brains could be readily detected at approximately 3 h after ischemia, as evidenced by its proteolytic cleavage and translocation to the mitochondria as determined using Western blot analysis and immunofluorescence staining. Correspondingly, mitochondrial release of cytochrome c could be detected around the same time Bid was cleaved in the wild-type brains. However, no significant cytochrome c release was detected in the bid-deficient brains until 24 h later. This suggests that, although the mitochondrial apoptosis pathway might be activated by multiple mechanisms during focal cerebral ischemia, Bid is critical to its early activation. This notion was further supported by the finding that caspase-3 activation was severely impaired in the bid-deficient brains, whereas activation of caspase-8 was much less affected. Taken together, these data suggest that Bid is activated early in neuronal ischemia in a caspase-8-dependent fashion and that Bid is perhaps one of the earliest and most potent activators of the mitochondrial apoptosis pathway. Thus, the role of Bid in the induction of ischemic neuronal death may render this molecule an attractive target for future therapeutic intervention.

Animals↗
PubMed2005

Mechanisms of plakoglobin-dependent adhesion: desmosome-specific functions in assembly and regulation by epidermal growth factor receptor.

Plakoglobin (PG) is a member of the Armadillo family of adhesion/signaling proteins that can be incorporated into both adherens junctions and desmosomes. Loss of PG results in defects in the mechanical integrity of heart and skin and decreased adhesive strength in keratinocyte cultures established from the skin of PG knock-out (PG-/-) mice, the latter of which cannot be compensated for by overexpressing the closely related beta-catenin. In this study, we examined the mechanisms of PG-regulated adhesion in murine keratinocytes. Biochemical and morphological analyses indicated that junctional incorporation of desmosomal, but not adherens junction, components was impaired in PG-/- cells compared with PG+/- controls. Re-expression of PG, but not beta-catenin, in PG-/- cells largely reversed these effects, indicating a key role for PG in desmosome assembly. Epidermal growth factor (EGF) receptor activation resulted in Tyr phosphorylation of PG, which was accompanied by a loss of desmoplakin from desmosomes and decreased adhesive strength following 18-h EGF treatment. Importantly, introduction of a phosphorylation-deficient PG mutant into PG null cells prevented the EGF receptor-dependent loss of desmoplakin from junctions, attenuating the effects of long term EGF treatment on cell adhesion. Therefore, PG is essential for maintaining and regulating adhesive strength in keratinocytes largely through its contributions to desmosome assembly and structure. As a target for modulation by EGF, regulation of PG-dependent adhesion may play an important role during wound healing and tumor metastasis.

Adenoviridae↗
PubMed2001

Phthalates rapidly increase production of reactive oxygen species in vivo: role of Kupffer cells.

The role of oxidants in the mechanism of tumor promotion by peroxisome proliferators remains controversial. The idea that induction of acyl-coenzyme A oxidase leads to increased production of H(2)O(2), which damages DNA, seems unlikely; still, free radicals might be important in signaling in specialized cell types such as Kupffer cells, which produce mitogens. Because hard evidence for increased oxidant production in vivo after treatment with peroxisome proliferators is lacking, the spin-trapping technique and electron spin resonance spectroscopy were used. Rats were given di(2-ethylhexyl) phthalate (DEHP) acutely. The spin trapping agent alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone was also given and bile samples were collected for 4 h. Under these conditions, the intensity of the six-line radical adduct signal increased to a maximum value of 2.5-fold 2 h after administration of DEHP, before peroxisomal oxidases were induced. Furthermore, DEHP given with [(13)C(2)]dimethyl sulfoxide produced a 12-line electron spin resonance spectrum, providing evidence that DEHP stimulates (*)OH radical formation in vivo. Furthermore, when rats were pretreated with dietary glycine, which inactivates Kupffer cells, DEHP did not increase radical signals. Moreover, similar treatments were performed in knockout mice deficient in NADPH oxidase (p47(phox) subunit). Importantly, DEHP increased oxidant production in wild-type but not in NADPH oxidase-deficient mice. These data provide evidence for the hypothesis that the molecular source of free radicals induced by peroxisome proliferators is NADPH oxidase in Kupffer cells. On the contrary, radical adduct formation was not affected in peroxisome proliferator-activated receptor alpha knockout mice. These observations represent the first direct, in vivo evidence that phthalates increase free radicals in liver before peroxisomal oxidases are induced.

Animals↗
PubMed2004

B7-CD28 interaction promotes proliferation and survival but suppresses differentiation of CD4-CD8- T cells in the thymus.

Costimulatory molecules play critical roles in the induction and effector function of T cells. More recent studies reveal that costimulatory molecules enhance clonal deletion of autoreactive T cells as well as generation and homeostasis of the CD25(+)CD4(+) regulatory T cells. However, it is unclear whether the costimulatory molecules play any role in the proliferation and differentiation of T cells before they acquire MHC-restricted TCR. In this study, we report that targeted mutations of B7-1 and B7-2 substantially reduce the proliferation and survival of CD4(-)CD8(-) (double-negative (DN)) T cells in the thymus. Perhaps as a result of reduced proliferation, the accumulation of RAG-2 protein in the DN thymocytes is increased in B7-deficient mice, which may explain the increased expression of TCR gene and accelerated transition of CD25(+)CD44(-) (DN3) to CD25(-)CD44(-) (DN4) stage. Qualitatively similar, but quantitatively less striking effects were observed in mice with a targeted mutation of CD28, but not CTLA4. Taken together, our results demonstrate that the development of DN in the thymus is subject to modulation by the B7-CD28 costimulatory pathway.

Animals↗
PubMed2004

Spectrum of hypermethioninemia in neonatal screening.

Measurement of methionine levels in dried blood spots has been one of the items of neonatal screening in Taiwan for more than 20 years. In 1,701,591 newborns, 17 cases of hypermethioninemia were detected, but among them only one had homocystinuria. More than half of the 16 cases of isolated hypermethioninemia had mutations in the MAT1A gene, and four of the eight MAT1A mutations identified in this study have not been reported before. Therefore methionine adenosyltransferase deficiency is the most prevalent cause of isolated hypermethioninemia in Taiwanese. Although most of the patients with isolated hypermethioninemia were put on diet in this study, their IQ scores were not related to either the initial or follow-up plasma methionine levels. Because both the etiology and the natural history of isolated hypermethioninemia haven't been clearly resolved, the impact of this condition on screening programs where homocystinuria is rare should be carefully evaluated.

Amino Acid Metabolism, Inborn Errors↗
PubMed2000

Bid-induced cytochrome c release is mediated by a pathway independent of mitochondrial permeability transition pore and Bax.

Bid, a pro-apoptosis "BH3-only" member of the Bcl-2 family, can be cleaved by caspase-8 after Fas/TNF-R1 engagement. The p15 form of truncated Bid (tBid) translocates to mitochondria and induces cytochrome c release, leading to the activation of downstream caspases and apoptosis. In the current study, we investigated the mechanism by which tBid regulated cytochrome c release in terms of its relationship to mitochondrial permeability transition and Bax, another Bcl-2 family protein. We employed an in vitro reconstitution system as well as cell cultures and an animal model to reflect the physiological environment where Bid could be functional. We found that induction of cytochrome c release by tBid was not accompanied by a permeability transition even at high doses. Indeed, inhibition of permeability transition did not suppress the activity of tBid in vitro nor could they block Fas activation-induced, Bid-dependent hepatocyte apoptosis in cultures. Furthermore, Mg(2+), although inhibiting permeability transition, actually enhanced the ability of tBid to induce cytochrome c release. We also found that tBid did not require Bax to induce cytochrome c release in vitro. In addition, mice deficient in bax were still highly susceptible to anti-Fas-induced hepatocyte apoptosis, in which cytochrome c release was unaffected. Moreover, although Bax-induced cytochrome c release was not dependent on tBid, the two proteins could function synergistically. We conclude that Bid possesses the biochemical activity to induce cytochrome c release through a mechanism independent of mitochondrial permeability transition pore and Bax.

Animals↗
PubMed2002

Relief of extrinsic pathway inhibition by the Bid-dependent mitochondrial release of Smac in Fas-mediated hepatocyte apoptosis.

The mitochondrial pathway is critical for the efficient execution of death receptor-initiated apoptosis in certain cell types. Questions remain as to why the mitochondria are required in that scenario. We investigated the molecular events that determined the need for the mitochondria by using an in vivo model of anti-Fas-induced hepatocyte apoptosis. In wild-type mice, Fas stimulation resulted in normal activation of caspase-3, with the generation of the active p19-p12 complex. In bid-deficient mice, caspase-3 activation was arrested after the initial cleavage at Asp(175). This allowed the generation of the p12 small subunit, but the p20 large subunit could not be further processed to the p19 subunit. The p20-p12 complex generated by Fas stimulation in bid-deficient hepatocytes was inactive, arresting the death program. Failure of p20/p12 caspase-3 to mature and to exhibit activity was because of the inhibition by the inhibitor-of-apoptosis proteins (IAPs), such as XIAP, and also to a low caspase-8 activity. This block could be overcome in wild-type mice by two mechanisms. Smac was released from mitochondria early following Fas activation and was competitively bound to the IAPs to reverse their effects. XIAP could also be cleaved, and this occurred later and was likely mediated by enhanced caspase activities. Both mechanisms were dependent on Bid and thus were not operative in bid-deficient hepatocytes. In conclusion, mitochondrial activation by Bid is required for reversing the IAP inhibition through Smac release. It is also required for the alternative activation of caspases through cytochrome c release, as demonstrated previously. Together, these events ensure a successful progression of the death program initiated by the death receptor activation in the hepatocyte.

Animals↗
PubMed2003

Post-transcriptional expression of DMT1 in the heart of rat.

Non-transferrin-bound iron (NTBI) overtaken by heart cells might be a key cause leading to iron-mediated injury in heart disorders. NTBI uptake by heart cells might be mediated by divalent metal transporter 1 (DMT1). The understanding of the role of DMT1 in heart iron metabolism is fundamental for elucidating the cause resulting in excessive iron in the heart. The study was to evaluate effects of age and dietary iron on DMT1 mRNA expression and protein synthesis in rat heart. DMT1 mRNA expression was determined by RT-PCR and sequence analysis, and DMT1 protein by Western blot analysis. DMT1 mRNAs with or without iron-responsive element (IRE) both were found in rat heart. Expression of two forms of DMT1 mRNAs was the lowest at the age of post-natal day (PND) 7, and then increased with the age, reaching the highest at PND196 (non-IRE form) and PND63 (IRE form), respectively. During different ages, the levels of DMT1 (IRE) mRNA were higher than those of DMT1 (non-IRE) mRNA and were significantly correlated with the non-heme iron contents in the heart. After fed a high iron for 6 weeks, the rats had a sixfold elevation in heart iron and 22% (non-IRE from) and 40% (IRE from) reduction in DMT1 protein compared to the controls. A low iron diet for 6-weeks caused cardiac hypertrophy and heart iron deficiency and also an increase in levels of two forms of DMT1 proteins. However, iron status had no significant effect on DMT1 (IRE) and DMT1 (non-IRE) mRNAs expression in the heart, although it can significantly influence heart transferrin receptor (TfR) mRNA expression. The results demonstrated that DMT1 mRNAs expression in the heart is age-dependent and that two forms of DMT1 mRNAs both are regulated by iron on the post-transcriptional level only.

Aging↗
PubMed2002

Ex vivo localization of the mouse saposin C activation region for acid beta-glucosidase.

Saposin C is a biological activator of acid beta-glucosidase (GCase), the lysosomal hydrolase with activity towards glucosylceramide (GC). In addition, saposin C possesses a functional domain that determines the in vitro and ex vivo neuritogenic effects of prosaposin, the precursor of saposins A, B, C, and D. The domains for enzymatic activation and neuritogenic function segregate in vitro, respectively, to the carboxyl- and amino-terminal halves of human and mouse saposin C. A chimeric mouse saposin C(1-8)B(8-28)C(30-80) was created to obliterate the neuritogenic region by substituting amino acids 9-29 of saposin C with amino acids 8-28 of saposin B. This saposin showed normal in vitro enzymatic activation effects toward GCase, but no neuritogenic activity. An altered prosaposin was made to contain the chimeric saposin C region. Expression of this altered or wild-type prosaposin was driven by the PGK-1 promoter as a transgene in prosaposin knock-out mice. In cultured fibroblasts from such mice, expressed saposins localized to the lysosomal compartments. Metabolic lipid labeling using L-[3-(14)C]serine showed retention or clearance of GC in prosaposin deficient or transgene reconstituted cells, respectively. In addition, sulfatide catabolism, that requires saposin B and arylsulfatase, was also normalized in prosaposin KO cells reconstituted with the transgenes. These data show that the transgenic prosaposins were expressed and processed to functional saposins in fibroblasts. These results also show that the enzymatic activation domain is located at carboxyl-terminal half of saposin C and functions only in the context of the general saposin structure.

Amino Acid Sequence↗