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2.
Pediatr Neurol ; 110: 64-70, 2020 09.
Article in English | MEDLINE | ID: mdl-32684372

ABSTRACT

BACKGROUND: Neuronal ceroid lipofuscinosis type 2 or CLN2 disease is a rare, autosomal recessive, neurodegenerative lysosomal storage disorder caused by tripeptidyl peptidase 1 deficiency. Cerliponase alfa, a recombinant human tripeptidyl peptidase 1 enzyme, is the first and only approved treatment for CLN2 disease and the first approved enzyme replacement therapy administered via intracerebroventricular infusion. METHODS: A meeting of health care professionals from US institutions with experience in cerliponase alfa treatment of children with CLN2 disease was held in November 2018. Key common practices were identified, and later refined during the drafting of this article, that facilitate safe chronic administration of cerliponase alfa. RESULTS: Key practices include developing a multidisciplinary team of clinicians, pharmacists, and coordinators, and institution-specific processes. Infection risk may be reduced through strict aseptic techniques and minimizing connections and disconnections during infusion. The impact of intracerebroventricular device design on port needle stability during extended intracerebroventricular infusion is a critical consideration in device selection. Monitoring for central nervous system infection is performed at each patient contact, but with flexibility in the degree of monitoring. Although few institutions had experienced positive cerebrospinal fluid test results, the response to a positive cerebrospinal fluid culture should be determined on a case-by-case basis, and the intracerebroventricular device should be removed if cerebrospinal fluid infection is confirmed. CONCLUSIONS: The key common practices and flexible practices used by institutions with cerliponase alfa experience may assist other institutions in process development. Continued sharing of experiences will be essential for developing standards and patient care guidelines.


Subject(s)
Aminopeptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/administration & dosage , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Infusion Pumps/standards , Infusions, Intraventricular , Neuronal Ceroid-Lipofuscinoses/drug therapy , Neurosurgical Procedures/standards , Patient Care Team , Practice Guidelines as Topic , Recombinant Proteins/administration & dosage , Serine Proteases/deficiency , Child , Humans , Infusion Pumps/adverse effects , Interdisciplinary Communication , Patient Care Team/standards , Tripeptidyl-Peptidase 1 , United States
3.
Cells ; 9(5)2020 05 20.
Article in English | MEDLINE | ID: mdl-32443895

ABSTRACT

CLN2 Batten disease (BD) is one of a broad class of lysosomal storage disorders that is characterized by the deficiency of lysosomal enzyme, TPP1, resulting in a build-up of toxic intracellular storage material in all organs and subsequent damage. A major challenge for BD therapeutics is delivery of enzymatically active TPP1 to the brain to attenuate progressive loss of neurological functions. To accomplish this daunting task, we propose the harnessing of naturally occurring nanoparticles, extracellular vesicles (EVs). Herein, we incorporated TPP1 into EVs released by immune cells, macrophages, and examined biodistribution and therapeutic efficacy of EV-TPP1 in BD mouse model, using various routes of administration. Administration through intrathecal and intranasal routes resulted in high TPP1 accumulation in the brain, decreased neurodegeneration and neuroinflammation, and reduced aggregation of lysosomal storage material in BD mouse model, CLN2 knock-out mice. Parenteral intravenous and intraperitoneal administrations led to TPP1 delivery to peripheral organs: liver, kidney, spleen, and lungs. A combination of intrathecal and intraperitoneal EV-TPP1 injections significantly prolonged lifespan in BD mice. Overall, the optimization of treatment strategies is crucial for successful applications of EVs-based therapeutics for BD.


Subject(s)
Drug Carriers/chemistry , Enzyme Replacement Therapy , Extracellular Vesicles/chemistry , Neuronal Ceroid-Lipofuscinoses/therapy , Aminopeptidases/deficiency , Aminopeptidases/metabolism , Animals , Brain/metabolism , Brain/pathology , Cells, Cultured , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/metabolism , Drug Administration Routes , Humans , Luminescent Measurements , Mice, Inbred C57BL , Mice, Knockout , Neurons/metabolism , Serine Proteases/deficiency , Serine Proteases/metabolism , Tissue Distribution , Treatment Outcome , Tripeptidyl-Peptidase 1
4.
Cell Rep ; 29(11): 3708-3725.e5, 2019 12 10.
Article in English | MEDLINE | ID: mdl-31825846

ABSTRACT

Telomeres use shelterin to protect chromosome ends from activating the DNA damage sensor MRE11-RAD50-NBS1 (MRN), repressing ataxia-telangiectasia, mutated (ATM) and ATM and Rad3-related (ATR) dependent DNA damage checkpoint responses. The MRE11 nuclease is thought to be essential for the resection of the 5' C-strand to generate the microhomologies necessary for alternative non-homologous end joining (A-NHEJ) repair. In the present study, we uncover DNA damage signaling and repair pathways engaged by components of the replisome complex to repair dysfunctional telomeres. In cells lacking MRN, single-stranded telomeric overhangs devoid of POT1-TPP1 do not recruit replication protein A (RPA), ATR-interacting protein (ATRIP), and RAD 51. Rather, components of the replisome complex, including Claspin, Proliferating cell nuclear antigen (PCNA), and Downstream neighbor of SON (DONSON), initiate DNA-PKcs-mediated p-CHK1 activation and A-NHEJ repair. In addition, Claspin directly interacts with TRF2 and recruits EXO1 to newly replicated telomeres to promote 5' end resection. Our data indicate that MRN is dispensable for the repair of dysfunctional telomeres lacking POT1-TPP1 and highlight the contributions of the replisome in telomere repair.


Subject(s)
DNA End-Joining Repair , DNA-Directed DNA Polymerase/metabolism , Multienzyme Complexes/metabolism , Telomere/metabolism , Acid Anhydride Hydrolases/metabolism , Adaptor Proteins, Signal Transducing/metabolism , Aminopeptidases/deficiency , Aminopeptidases/metabolism , Animals , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cells, Cultured , Checkpoint Kinase 1/metabolism , DNA Repair Enzymes/metabolism , DNA-Binding Proteins/metabolism , DNA-Directed DNA Polymerase/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/metabolism , Exodeoxyribonucleases/metabolism , HEK293 Cells , Humans , MRE11 Homologue Protein/metabolism , Mice , Multienzyme Complexes/genetics , Proliferating Cell Nuclear Antigen/metabolism , Serine Proteases/deficiency , Serine Proteases/metabolism , Shelterin Complex , Telomere/genetics , Telomere-Binding Proteins/deficiency , Telomere-Binding Proteins/metabolism , Telomeric Repeat Binding Protein 2/metabolism
5.
J Bone Miner Res ; 34(11): 2133-2148, 2019 11.
Article in English | MEDLINE | ID: mdl-31295380

ABSTRACT

Controlling oxidative stress through the activation of antioxidant pathways is crucial in bone homeostasis, and impairments of the cellular defense systems involved contribute to the pathogenesis of common skeletal diseases. In this work we focused on the dipeptidyl peptidase 3 (DPP3), a poorly investigated ubiquitous zinc-dependent exopeptidase activating the Keap1-Nrf2 antioxidant pathway. We showed Dpp3 expression in bone and, to understand its role in this compartment, we generated a Dpp3 knockout (KO) mouse model and specifically investigated the skeletal phenotype. Adult Dpp3 KO mice showed a mild growth defect, a significant increase in bone marrow cellularity, and bone loss mainly caused by increased osteoclast activity. Overall, in the mouse model, lack of DPP3 resulted in sustained oxidative stress and in alterations of bone microenvironment favoring the osteoclast compared to the osteoblast lineage. Accordingly, in vitro studies revealed that Dpp3 KO osteoclasts had an inherent increased resorptive activity and ROS production, which on the other hand made them prone to apoptosis. Moreover, absence of DPP3 augmented bone loss after estrogen withdrawal in female mice, further supporting its relevance in the framework of bone pathophysiology. Overall, we show a nonredundant role for DPP3 in the maintenance of bone homeostasis and propose that DPP3 might represent a possible new osteoimmunological player and a marker of human bone loss pathology. © 2019 American Society for Bone and Mineral Research.


Subject(s)
Bone Resorption , Cellular Microenvironment , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Osteoclasts , Oxidative Stress , Signal Transduction , Animals , Bone Resorption/genetics , Bone Resorption/metabolism , Bone Resorption/pathology , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/metabolism , Humans , Kelch-Like ECH-Associated Protein 1/genetics , Kelch-Like ECH-Associated Protein 1/metabolism , Mice , Mice, Knockout , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Osteoclasts/metabolism , Osteoclasts/pathology
6.
Sci Rep ; 9(1): 7292, 2019 05 13.
Article in English | MEDLINE | ID: mdl-31086209

ABSTRACT

The ubiquitous intracellular protease dipeptidyl peptidase 9 (DPP9) has roles in antigen presentation and B cell signaling. To investigate the importance of DPP9 in immune regeneration, primary and secondary chimeric mice were created in irradiated recipients using fetal liver cells and adult bone marrow cells, respectively, using wild-type (WT) and DPP9 gene-knockin (DPP9S729A) enzyme-inactive mice. Immune cell reconstitution was assessed at 6 and 16 weeks post-transplant. Primary chimeric mice successfully regenerated neutrophils, natural killer, T and B cells, irrespective of donor cell genotype. There were no significant differences in total myeloid cell or neutrophil numbers between DPP9-WT and DPP9S729A-reconstituted mice. In secondary chimeric mice, cells of DPP9S729A-origin cells displayed enhanced engraftment compared to WT. However, we observed no differences in myeloid or lymphoid lineage reconstitution between WT and DPP9S729A donors, indicating that hematopoietic stem cell (HSC) engraftment and self-renewal is not diminished by the absence of DPP9 enzymatic activity. This is the first report on transplantation of bone marrow cells that lack DPP9 enzymatic activity.


Subject(s)
Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Hematopoietic Stem Cells/physiology , Immune Reconstitution/physiology , Lymphocytes/immunology , Neutrophils/immunology , Animals , Bone Marrow Transplantation , Catalytic Domain/genetics , Cell Differentiation/immunology , Cell Proliferation , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Female , Fetus , Gene Knock-In Techniques , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells/radiation effects , Immune System/radiation effects , Liver/cytology , Loss of Function Mutation , Lymphocytes/radiation effects , Male , Mice , Mice, Transgenic , Models, Animal , Neutrophils/radiation effects , Point Mutation , Transplantation Chimera/immunology , Whole-Body Irradiation
7.
Acta Neuropathol ; 137(6): 901-918, 2019 06.
Article in English | MEDLINE | ID: mdl-30874922

ABSTRACT

Emerging evidence suggested a converging mechanism in neurodegenerative brain diseases (NBD) involving early neuronal network dysfunctions and alterations in the homeostasis of neuronal firing as culprits of neurodegeneration. In this study, we used paired-end short-read and direct long-read whole genome sequencing to investigate an unresolved autosomal dominant dementia family significantly linked to 7q36. We identified and validated a chromosomal inversion of ca. 4 Mb, segregating on the disease haplotype and disrupting the coding sequence of dipeptidyl-peptidase 6 gene (DPP6). DPP6 resequencing identified significantly more rare variants-nonsense, frameshift, and missense-in early-onset Alzheimer's disease (EOAD, p value = 0.03, OR = 2.21 95% CI 1.05-4.82) and frontotemporal dementia (FTD, p = 0.006, OR = 2.59, 95% CI 1.28-5.49) patient cohorts. DPP6 is a type II transmembrane protein with a highly structured extracellular domain and is mainly expressed in brain, where it binds to the potassium channel Kv4.2 enhancing its expression, regulating its gating properties and controlling the dendritic excitability of hippocampal neurons. Using in vitro modeling, we showed that the missense variants found in patients destabilize DPP6 and reduce its membrane expression (p < 0.001 and p < 0.0001) leading to a loss of protein. Reduced DPP6 and/or Kv4.2 expression was also detected in brain tissue of missense variant carriers. Loss of DPP6 is known to cause neuronal hyperexcitability and behavioral alterations in Dpp6-KO mice. Taken together, the results of our genomic, genetic, expression and modeling analyses, provided direct evidence supporting the involvement of DPP6 loss in dementia. We propose that loss of function variants have a higher penetrance and disease impact, whereas the missense variants have a variable risk contribution to disease that can vary from high to low penetrance. Our findings of DPP6, as novel gene in dementia, strengthen the involvement of neuronal hyperexcitability and alteration in the homeostasis of neuronal firing as a disease mechanism to further investigate.


Subject(s)
Chromosome Inversion , Dementia/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Mutation , Nerve Tissue Proteins/deficiency , Neurodegenerative Diseases/genetics , Neurons/physiology , Potassium Channels/deficiency , Action Potentials/physiology , Adult , Aged , Chromosomes, Human, Pair 7/genetics , Dementia/physiopathology , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/physiology , Female , Genes, Dominant , Homeostasis , Humans , Male , Middle Aged , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/physiology , Neurodegenerative Diseases/physiopathology , Pedigree , Penetrance , Polymorphism, Single Nucleotide , Potassium Channels/genetics , Potassium Channels/physiology , Protein Stability , Protein Transport , Synaptic Transmission , Whole Genome Sequencing
8.
Acta Neuropathol Commun ; 5(1): 74, 2017 10 17.
Article in English | MEDLINE | ID: mdl-29041969

ABSTRACT

The neuronal ceroid lipofuscinoses (NCLs or Batten disease) are a group of inherited, fatal neurodegenerative disorders of childhood. In these disorders, glial (microglial and astrocyte) activation typically occurs early in disease progression and predicts where neuron loss subsequently occurs. We have found that in the most common juvenile form of NCL (CLN3 disease or JNCL) this glial response is less pronounced in both mouse models and human autopsy material, with the morphological transformation of both astrocytes and microglia severely attenuated or delayed. To investigate their properties, we isolated glia and neurons from Cln3-deficient mice and studied their basic biology in culture. Upon stimulation, both Cln3-deficient astrocytes and microglia also showed an attenuated ability to transform morphologically, and an altered protein secretion profile. These defects were more pronounced in astrocytes, including the reduced secretion of a range of neuroprotective factors, mitogens, chemokines and cytokines, in addition to impaired calcium signalling and glutamate clearance. Cln3-deficient neurons also displayed an abnormal organization of their neurites. Most importantly, using a co-culture system, Cln3-deficient astrocytes and microglia had a negative impact on the survival and morphology of both Cln3-deficient and wildtype neurons, but these effects were largely reversed by growing mutant neurons with healthy glia. These data provide evidence that CLN3 disease astrocytes are functionally compromised. Together with microglia, they may play an active role in neuron loss in this disorder and can be considered as potential targets for therapeutic interventions.


Subject(s)
Brain/physiopathology , Neuroglia/physiology , Neuronal Ceroid-Lipofuscinoses/physiopathology , Neurons/physiology , Adult , Aminopeptidases/deficiency , Aminopeptidases/genetics , Animals , Brain/pathology , Cell Movement/physiology , Cell Survival/physiology , Cells, Cultured , Child , Coculture Techniques , Cytoskeleton/metabolism , Cytoskeleton/pathology , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Female , Glutathione/metabolism , Humans , Male , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Mice, Inbred C57BL , Mice, Transgenic , Molecular Chaperones/genetics , Neuroglia/pathology , Neuronal Ceroid-Lipofuscinoses/pathology , Neurons/pathology , Serine Proteases/deficiency , Serine Proteases/genetics , Tripeptidyl-Peptidase 1 , Young Adult
9.
J Proteome Res ; 16(10): 3787-3804, 2017 10 06.
Article in English | MEDLINE | ID: mdl-28792770

ABSTRACT

Clinical trials have been conducted for the neuronal ceroid lipofuscinoses (NCLs), a group of neurodegenerative lysosomal diseases that primarily affect children. Whereas clinical rating systems will evaluate long-term efficacy, biomarkers to measure short-term response to treatment would be extremely valuable. To identify candidate biomarkers, we analyzed autopsy brain and matching CSF samples from controls and three genetically distinct NCLs due to deficiencies in palmitoyl protein thioesterase 1 (CLN1 disease), tripeptidyl peptidase 1 (CLN2 disease), and CLN3 protein (CLN3 disease). Proteomic and biochemical methods were used to analyze lysosomal proteins, and, in general, we find that changes in protein expression compared with control were most similar between CLN2 disease and CLN3 disease. This is consistent with previous observations of biochemical similarities between these diseases. We also conducted unbiased proteomic analyses of CSF and brain using isobaric labeling/quantitative mass spectrometry. Significant alterations in protein expression were identified in each NCL, including reduced STXBP1 in CLN1 disease brain. Given the confounding variable of post-mortem changes, additional validation is required, but this study provides a useful starting set of candidate NCL biomarkers for further evaluation.


Subject(s)
Brain/metabolism , Munc18 Proteins/genetics , Neuronal Ceroid-Lipofuscinoses/genetics , Proteomics , Aminopeptidases/deficiency , Aminopeptidases/genetics , Autopsy , Biomarkers/cerebrospinal fluid , Biomarkers/chemistry , Biomarkers/metabolism , Brain/pathology , Cerebrospinal Fluid/chemistry , Cerebrospinal Fluid/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Humans , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Membrane Proteins/deficiency , Membrane Proteins/genetics , Molecular Chaperones/genetics , Munc18 Proteins/deficiency , Mutation , Neuronal Ceroid-Lipofuscinoses/cerebrospinal fluid , Neuronal Ceroid-Lipofuscinoses/metabolism , Neuronal Ceroid-Lipofuscinoses/pathology , Serine Proteases/deficiency , Serine Proteases/genetics , Thiolester Hydrolases/deficiency , Thiolester Hydrolases/genetics , Tripeptidyl-Peptidase 1
10.
Mol Ther ; 25(7): 1531-1543, 2017 07 05.
Article in English | MEDLINE | ID: mdl-28456380

ABSTRACT

We have investigated delivery of protein therapeutics from the bloodstream into the brain using a mouse model of late-infantile neuronal ceroid lipofuscinosis (LINCL), a lysosomal disease due to deficiencies in tripeptidyl peptidase 1 (TPP1). Supraphysiological levels of TPP1 are delivered to the mouse brain by acute intravenous injection when co-administered with K16ApoE, a peptide that in trans mediates passage across the blood-brain barrier (BBB). Chronic treatment of LINCL mice with TPP1 and K16ApoE extended the lifespan from 126 to >294 days, diminished pathology, and slowed locomotor dysfunction. K16ApoE enhanced uptake of a fixable biotin tracer by brain endothelial cells in a dose-dependent manner, suggesting that its mechanism involves stimulation of endocytosis. Pharmacokinetic experiments indicated that K16ApoE functions without disrupting the BBB, with minimal effects on overall clearance or uptake by the liver and kidney. K16ApoE has a narrow therapeutic index, with toxicity manifested as lethargy and/or death in mice. To address this, we evaluated variant peptides but found that efficacy and toxicity are associated, suggesting that desired and adverse effects are mechanistically related. Toxicity currently precludes direct clinical application of peptide-mediated delivery in its present form but it remains a useful approach to proof-of-principle studies for biologic therapies to the brain in animal models.


Subject(s)
Aminopeptidases/genetics , Apolipoproteins E/pharmacokinetics , Blood-Brain Barrier/drug effects , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Drug Carriers , Neuronal Ceroid-Lipofuscinoses/therapy , Peptides/pharmacokinetics , Serine Proteases/genetics , Amino Acid Sequence , Aminopeptidases/deficiency , Animals , Apolipoproteins E/chemistry , Blood-Brain Barrier/metabolism , Brain/drug effects , Brain/enzymology , Brain/pathology , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Disease Models, Animal , Endocytosis , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Endothelial Cells/pathology , Enzyme Replacement Therapy/methods , Gene Expression Regulation , Humans , Infant , Injections, Intravenous , Mice , Neuronal Ceroid-Lipofuscinoses/enzymology , Neuronal Ceroid-Lipofuscinoses/genetics , Neuronal Ceroid-Lipofuscinoses/pathology , Peptides/chemistry , Serine Proteases/deficiency , Survival Analysis , Treatment Outcome , Tripeptidyl-Peptidase 1
11.
Sci Transl Med ; 7(313): 313ra180, 2015 Nov 11.
Article in English | MEDLINE | ID: mdl-26560358

ABSTRACT

The most common form of the childhood neurodegenerative disease late infantile neuronal ceroid lipofuscinosis (also called Batten disease) is caused by deficiency of the soluble lysosomal enzyme tripeptidyl peptidase 1 (TPP1) resulting from mutations in the TPP1 gene. We tested whether TPP1 gene transfer to the ependyma, the epithelial lining of the brain ventricular system, in TPP1-deficient dogs would be therapeutically beneficial. A one-time administration of recombinant adeno-associated virus (rAAV) expressing canine TPP1 (rAAV.caTPP1) resulted in high expression of TPP1 predominantly in ependymal cells and secretion of the enzyme into the cerebrospinal fluid leading to clinical benefit. Diseased dogs treated with rAAV.caTPP1 showed delays in onset of clinical signs and disease progression, protection from cognitive decline, and extension of life span. By immunostaining and enzyme assay, recombinant protein was evident throughout the brain and spinal cord, with correction of the neuropathology characteristic of the disease. This study in a naturally occurring canine model of TPP1 deficiency highlights the utility of AAV transduction of ventricular lining cells to accomplish stable secretion of recombinant protein for broad distribution in the central nervous system and therapeutic benefit.


Subject(s)
Aminopeptidases/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Enzyme Replacement Therapy , Neuronal Ceroid-Lipofuscinoses/genetics , Neuronal Ceroid-Lipofuscinoses/therapy , Serine Proteases/genetics , Transduction, Genetic , Aminopeptidases/cerebrospinal fluid , Aminopeptidases/deficiency , Animals , Cerebral Ventricles/metabolism , Dependovirus/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/cerebrospinal fluid , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Disease Models, Animal , Dogs , Genetic Vectors/administration & dosage , Serine Proteases/cerebrospinal fluid , Serine Proteases/deficiency , Tripeptidyl-Peptidase 1
13.
Blood ; 125(5): 753-61, 2015 Jan 29.
Article in English | MEDLINE | ID: mdl-25414442

ABSTRACT

Autoimmune cytopenia is a frequent manifestation of primary immunodeficiencies. Two siblings presented with Evans syndrome, viral infections, and progressive leukopenia. DNA available from one patient showed a homozygous frameshift mutation in tripeptidyl peptidase II (TPP2) abolishing protein expression. TPP2 is a serine exopeptidase involved in extralysosomal peptide degradation. Its deficiency in mice activates cell death programs and premature senescence. Similar to cells from naïve, uninfected TPP2-deficient mice, patient cells showed increased major histocompatibility complex I expression and most CD8(+) T-cells had a senescent CCR7-CD127(-)CD28(-)CD57(+) phenotype with poor proliferative responses and enhanced staurosporine-induced apoptosis. T-cells showed increased expression of the effector molecules perforin and interferon-γ with high expression of the transcription factor T-bet. Age-associated B-cells with a CD21(-) CD11c(+) phenotype expressing T-bet were increased in humans and mice, combined with antinuclear antibodies. Moreover, markers of senescence were also present in human and murine TPP2-deficient fibroblasts. Telomere lengths were normal in patient fibroblasts and granulocytes, and low normal in lymphocytes, which were compatible with activation of stress-induced rather than replicative senescence programs. TPP2 deficiency is the first primary immunodeficiency linking premature immunosenescence to severe autoimmunity. Determination of senescent lymphocytes should be part of the diagnostic evaluation of children with refractory multilineage cytopenias.


Subject(s)
Aging/immunology , Aminopeptidases/immunology , Anemia, Hemolytic, Autoimmune/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/immunology , Frameshift Mutation , Immunologic Deficiency Syndromes/genetics , Serine Endopeptidases/immunology , Thrombocytopenia/genetics , Aminopeptidases/deficiency , Aminopeptidases/genetics , Anemia, Hemolytic, Autoimmune/complications , Anemia, Hemolytic, Autoimmune/immunology , Anemia, Hemolytic, Autoimmune/pathology , Animals , Apoptosis , Base Sequence , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/pathology , Child , Child, Preschool , Consanguinity , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Female , Fibroblasts/immunology , Fibroblasts/metabolism , Fibroblasts/pathology , Gene Expression , Humans , Immunologic Deficiency Syndromes/complications , Immunologic Deficiency Syndromes/immunology , Immunologic Deficiency Syndromes/pathology , Male , Mice , Mice, Knockout , Molecular Sequence Data , Perforin/genetics , Perforin/immunology , Serine Endopeptidases/deficiency , Serine Endopeptidases/genetics , Siblings , T-Box Domain Proteins/genetics , T-Box Domain Proteins/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , T-Lymphocytes/pathology , Thrombocytopenia/complications , Thrombocytopenia/immunology , Thrombocytopenia/pathology
14.
Exp Eye Res ; 125: 164-72, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24954537

ABSTRACT

Late-infantile neuronal ceroid lipofuscinosis (CLN2 disease) is a hereditary neurological disorder characterized by progressive retinal degeneration and vision loss, cognitive and motor decline, seizures, and pronounced brain atrophy. This fatal pediatric disease is caused by mutations in the CLN2 gene which encodes the lysosomal enzyme tripeptidyl peptidase-1 (TPP1). Utilizing a TPP1-/- Dachshund model of CLN2 disease, studies were conducted to assess the effects of TPP1 enzyme replacement administered directly to the CNS on disease progression. Recombinant human TPP1 (rhTPP1) or artificial cerebrospinal fluid vehicle was administered to CLN2-affected dogs via infusion into the CSF. Untreated and vehicle treated affected dogs exhibited progressive declines in pupillary light reflexes (PLRs) and electroretinographic (ERG) responses to light stimuli. Studies were undertaken to determine whether CSF administration of rhTPP1 alters progression of the PLR and ERG deficits in the canine model. rhTPP1 administration did not inhibit the decline in ERG responses, as rhTPP1 treated, vehicle treated, and untreated dogs all exhibited similar progressive and profound declines in ERG amplitudes. However, in some of the dogs treated with rhTPP1 there were substantial delays in the appearance and progression of PLR deficits compared with untreated or vehicle treated affected dogs. These findings indicate that CSF administration of TPP1 can attenuate functional impairment of neural pathways involved in mediating the PLR but does not prevent loss of retinal responses detectable with ERG.


Subject(s)
Aminopeptidases/therapeutic use , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/therapeutic use , Enzyme Replacement Therapy , Neuronal Ceroid-Lipofuscinoses/drug therapy , Reflex, Pupillary/drug effects , Serine Proteases/therapeutic use , Aminopeptidases/deficiency , Analysis of Variance , Animals , Axons , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Disease Models, Animal , Disease Progression , Dogs , Electroretinography/drug effects , Neuronal Ceroid-Lipofuscinoses/physiopathology , Optic Nerve/cytology , Recombinant Proteins/therapeutic use , Serine Proteases/deficiency , Tripeptidyl-Peptidase 1
15.
PLoS One ; 8(11): e78378, 2013.
Article in English | MEDLINE | ID: mdl-24223149

ABSTRACT

Dipeptidyl Peptidase (DPP) 4 and related dipeptidyl peptidases are emerging as current and potential therapeutic targets. DPP9 is an intracellular protease that is regulated by redox status and by SUMO1. DPP9 can influence antigen processing, epidermal growth factor (EGF)-mediated signaling and tumor biology. We made the first gene knock-in (gki) mouse with a serine to alanine point mutation at the DPP9 active site (S729A). Weaned heterozygote DPP9 (wt/S729A) pups from 110 intercrosses were indistinguishable from wild-type littermates. No homozygote DPP9 (S729A/S729A) weaned mice were detected. DPP9 (S729A/S729A) homozygote embryos, which were morphologically indistinguishable from their wild-type littermate embryos at embryonic day (ED) 12.5 to ED 17.5, were born live but these neonates died within 8 to 24 hours of birth. All neonates suckled and contained milk spots and were of similar body weight. No gender differences were seen. No histological or DPP9 immunostaining pattern differences were seen between genotypes in embryos and neonates. Mouse embryonic fibroblasts (MEFs) from DPP9 (S729A/S729A) ED13.5 embryos and neonate DPP9 (S729A/S729A) mouse livers collected within 6 hours after birth had levels of DPP9 protein and DPP9-related proteases that were similar to wild-type but had less DPP9/DPP8-derived activity. These data confirmed the absence of DPP9 enzymatic activity due to the presence of the serine to alanine mutation and no compensation from related proteases. These novel findings suggest that DPP9 enzymatic activity is essential for early neonatal survival in mice.


Subject(s)
Animals, Newborn/abnormalities , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Mice, Transgenic/genetics , Point Mutation , Amino Acid Substitution , Animals , Animals, Newborn/genetics , Animals, Newborn/metabolism , Crosses, Genetic , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Embryo, Mammalian , Enzyme Assays , Female , Fibroblasts/enzymology , Founder Effect , Gene Expression , Gene Knock-In Techniques , Heterozygote , Homozygote , Liver/enzymology , Male , Mice , Mice, Transgenic/abnormalities , Mice, Transgenic/metabolism
16.
Nat Commun ; 4: 2270, 2013.
Article in English | MEDLINE | ID: mdl-23912628

ABSTRACT

Dipeptidyl-peptidase 6 is an auxiliary subunit of Kv4-mediated A-type K(+) channels that, in addition to enhancing channel surface expression, potently accelerates their kinetics. The dipeptidyl-peptidase 6 gene has been associated with a number of human central nervous system disorders including autism spectrum disorders and schizophrenia. Here we employ knockdown and genetic deletion of dipeptidyl-peptidase 6 to reveal its importance for the formation and stability of dendritic filopodia during early neuronal development. We find that the hippocampal neurons lacking dipeptidyl-peptidase 6 show a sparser dendritic branching pattern along with fewer spines throughout development and into adulthood. In electrophysiological and imaging experiments, we show that these deficits lead to fewer functional synapses and occur independently of the potassium channel subunit Kv4.2. We report that dipeptidyl-peptidase 6 interacts with a filopodia-associated myosin as well as with fibronectin in the extracellular matrix. dipeptidyl-peptidase 6 therefore has an unexpected but important role in cell adhesion and motility, impacting the hippocampal synaptic development and function.


Subject(s)
Dendrites/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/metabolism , Hippocampus/metabolism , Morphogenesis , Synapses/metabolism , Animals , CA1 Region, Hippocampal/metabolism , Cell Adhesion , Dendritic Spines/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Extracellular Matrix/metabolism , Fibronectins/metabolism , Gene Knockdown Techniques , Humans , Immunoprecipitation , Mice , Mice, Knockout , Protein Binding , Pseudopodia/metabolism , Rats , Rats, Sprague-Dawley , Shal Potassium Channels/metabolism
17.
Brain ; 136(Pt 5): 1488-507, 2013 May.
Article in English | MEDLINE | ID: mdl-23587805

ABSTRACT

Tripeptidyl peptidase 1 (TPP1) deficiency causes CLN2 disease, late infantile (or classic late infantile neuronal ceroid lipofuscinosis), a paediatric neurodegenerative disease of autosomal recessive inheritance. Patients suffer from blindness, ataxia, epilepsy and cognitive defects, with MRI indicating widespread brain atrophy, and profound neuron loss is evident within the retina and brain. Currently there are no effective therapies for this disease, which causes premature death in adolescence. Zebrafish have been successfully used to model a range of neurological and behavioural abnormalities. The aim of this study was to characterize the pathological and functional consequences of Tpp1 deficiency in zebrafish and to correlate these with human CLN2 disease, thereby providing a platform for drug discovery. Our data show that homozygous tpp1(sa0011) mutant (tpp1(sa0011)(-/-)) zebrafish display a severe, progressive, early onset neurodegenerative phenotype, characterized by a significantly small retina, a small head and curved body. The mutant zebrafish have significantly reduced median survival with death occurring 5 days post-fertilization. As in human patients with CLN2 disease, mutant zebrafish display storage of subunit c of mitochondrial ATP-synthase, hypertrophic lysosomes as well as localized apoptotic cell death in the retina, optic tectum and cerebellum. Further neuropathological phenotypes of these mutants provide novel insights into mechanisms of pathogenesis in CLN2 disease. Secondary neurogenesis in the retina, optic tectum and cerebellum is impaired and axon tracts within the spinal cord, optic nerve and the posterior commissure are disorganized, with the optic nerve failing to reach its target. This severe neurodegenerative phenotype eventually results in functional motor impairment, but this is preceded by a phase of hyperactivity that is consistent with seizures. Importantly, both of these locomotion phenotypes can be assayed in an automated manner suitable for high-throughput studies. Our study provides proof-of-principle that tpp1(sa0011)(-/-) mutants can utilize the advantages of zebrafish for understanding pathogenesis and drug discovery in CLN2 disease and other epilepsies.


Subject(s)
Aminopeptidases/deficiency , Cell Proliferation , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Disease Progression , Neuronal Ceroid-Lipofuscinoses/enzymology , Neuronal Ceroid-Lipofuscinoses/pathology , Serine Proteases/deficiency , Aminopeptidases/genetics , Aminopeptidases/physiology , Animals , Animals, Genetically Modified , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/physiology , Disease Models, Animal , Growth Inhibitors/deficiency , Growth Inhibitors/genetics , Growth Inhibitors/physiology , Humans , Motor Activity/physiology , Neurodegenerative Diseases/enzymology , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/pathology , Neuronal Ceroid-Lipofuscinoses/genetics , Serine Proteases/genetics , Serine Proteases/physiology , Tripeptidyl-Peptidase 1 , Zebrafish
18.
Biosci Rep ; 33(2): e00023, 2013 Feb 07.
Article in English | MEDLINE | ID: mdl-23249249

ABSTRACT

NCLs (neuronal ceroid lipofuscinoses) form a group of eight inherited autosomal recessive diseases characterized by the intralysosomal accumulation of autofluorescent pigments, called ceroids. Recent data suggest that the pathogenesis of NCL is associated with the appearance of fragmented mitochondria with altered functions. However, even if an impairement in the autophagic pathway has often been evoked, the molecular mechanisms leading to mitochondrial fragmentation in response to a lysosomal dysfunction are still poorly understood. In this study, we show that fibroblasts that are deficient for the TPP-1 (tripeptidyl peptidase-1), a lysosomal hydrolase encoded by the gene mutated in the LINCL (late infantile NCL, CLN2 form) also exhibit a fragmented mitochondrial network. This morphological alteration is accompanied by an increase in the expression of the protein BNIP3 (Bcl2/adenovirus E1B 19 kDa interacting protein 3) as well as a decrease in the abundance of mitofusins 1 and 2, two proteins involved in mitochondrial fusion. Using RNAi (RNA interference) and quantitative analysis of the mitochondrial morphology, we show that the inhibition of BNIP3 expression does not result in an increase in the reticulation of the mitochondrial population in LINCL cells. However, this protein seems to play a key role in cell response to mitochondrial oxidative stress as it sensitizes mitochondria to antimycin A-induced fragmentation. To our knowledge, our results bring the first evidence of a mechanism that links TPP-1 deficiency and oxidative stress-induced changes in mitochondrial morphology.


Subject(s)
Aminopeptidases/genetics , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/genetics , Mitochondria/metabolism , Neuronal Ceroid-Lipofuscinoses/metabolism , Oxidative Stress/genetics , Serine Proteases/genetics , Aminopeptidases/deficiency , Autophagy/genetics , Cells, Cultured , Ceroid/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Fibroblasts/metabolism , Fibroblasts/pathology , Humans , Lysosomes/metabolism , Lysosomes/pathology , Mitochondria/drug effects , Mitochondria/pathology , Neuronal Ceroid-Lipofuscinoses/pathology , Serine Proteases/deficiency , Tripeptidyl-Peptidase 1
19.
J Gen Appl Microbiol ; 58(3): 199-209, 2012.
Article in English | MEDLINE | ID: mdl-22878738

ABSTRACT

Proteolytic degradation is one of the serious bottlenecks limiting the yields of heterologous protein production by Aspergillus oryzae. In this study, we selected a tripeptidyl peptidase gene AosedD (AO090166000084) as a candidate potentially degrading the heterologous protein, and performed localization analysis of the fusion protein AoSedD-EGFP in A. oryzae. As a result, the AoSedD-EGFP was observed in the septa and cell walls as well as in the culture medium, suggesting that AoSedD is a secretory enzyme. An AosedD disruptant was constructed to investigate an effect of AoSedD on the production level of heterologous proteins and protease activity. Both of the total protease and tripeptidyl peptidase activities in the culture medium of the AosedD disruptant were decreased as compared to those of the control strain. The maximum yields of recombinant bovine chymosin (CHY) and human lysozyme (HLY) produced by the AosedD disruptants showed approximately 2.9- and 1.7-fold increases, respectively, as compared to their control strains. These results suggest that AoSedD is one of the major proteases involved in the proteolytic degradation of recombinant proteins in A. oryzae.


Subject(s)
Aspergillus oryzae/genetics , Aspergillus oryzae/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Gene Knockout Techniques , Metabolic Engineering , Recombinant Proteins/biosynthesis , Aspergillus oryzae/enzymology , Cell Wall/enzymology , Culture Media/chemistry , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/metabolism
20.
Neurol India ; 60(3): 316-20, 2012.
Article in English | MEDLINE | ID: mdl-22824694

ABSTRACT

Neuronal ceroid lipofuscinosis is a group of progressive neurodegenerative disorders characterized by accumulation of ceroid lipopigment in lysosomes in neurons and other cell types. This study is a retrospective review of charts of patients with a diagnosis of infantile and late-infantile neuronal ceroid lipofuscinosis seen between January 2009 and December 2011. Of the 16 patients, 5 had infantile type and 11 had late-infantile neuronal ceroid lipofuscinosis. Diagnosis was confirmed by appropriate enzyme assay. Clinical presentation was quite varied. Common presenting features included refractory seizures, developmental delay/regression, and abnormal movements. Visual failure was not common in the present case series, and novel neuroimaging finding in the form of isolated dentate nucleus hyperintensities were noted. During follow-up, all patients had a progressive downhill course and one patient died. Prenatal diagnosis could be offered to one family. This study suggests that infantile and late-infantile neuronal ceroid lipofuscinosis is not uncommon in this region of the country and the phenotype may be different.


Subject(s)
Neuronal Ceroid-Lipofuscinoses/diagnosis , Neuronal Ceroid-Lipofuscinoses/physiopathology , Age of Onset , Aminopeptidases/deficiency , Child , Child, Preschool , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/deficiency , Female , Humans , Infant , Longitudinal Studies , Magnetic Resonance Imaging , Male , Neuronal Ceroid-Lipofuscinoses/enzymology , Retrospective Studies , Serine Proteases/deficiency , Tripeptidyl-Peptidase 1
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