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JIMD Reports May 2024Methionine synthase reductase deficiency (cblE) is a rare autosomal recessive inborn error of cobalamin metabolism caused by pathogenic variants in the methionine...
Late-onset refractory hemolytic anemia in siblings treated for methionine synthase reductase deficiency: A rare complication possibly prevented by hydroxocobalamin dose escalation?
Methionine synthase reductase deficiency (cblE) is a rare autosomal recessive inborn error of cobalamin metabolism caused by pathogenic variants in the methionine synthase reductase gene (). Patients usually exhibit early-onset bone marrow failure with pancytopenia including megaloblastic anemia. The latter can remain isolated or patients may present developmental delay and rarely macular dysfunction. Treatment mostly includes parenteral hydroxocobalamin to maximize the residual enzyme function and betaine to increase methionine concentrations and decrease homocysteine accumulation. We report herein 2 cblE siblings diagnosed in the neonatal period with isolated pancytopenia who, despite treatment, exhibited in adulthood hemolytic anemia (LDH >11 000 U/L, undetectable haptoglobin, elevated unconjugated bilirubin) which could finally be successfully treated by hydroxocobalamin dose escalation. There was no obvious trigger apart from a parvovirus B19 infection in one of the patients. This is the first report of such complications in adulthood. The use of LDH for disease monitoring could possibly be an additional useful biomarker to adjust hydroxocobalamin dosage. Bone marrow infection with parvovirus B19 can complicate this genetic disease with erythroblastopenia even in the absence of an immunocompromised status, as in other congenital hemolytic anemias. The observation of novel hemolytic features in this rare disease should raise awareness about specific complications in remethylation disorders and plea for hydroxocobalamin dose escalation.
PubMed: 38736634
DOI: 10.1002/jmd2.12422 -
International Journal of Molecular... Apr 2024Fatty acid desaturase 1 (FADS1) is a rate-limiting enzyme in long-chain polyunsaturated fatty acid (LCPUFA) synthesis. Reduced activity of FADS1 was observed in...
Fatty acid desaturase 1 (FADS1) is a rate-limiting enzyme in long-chain polyunsaturated fatty acid (LCPUFA) synthesis. Reduced activity of FADS1 was observed in metabolic dysfunction-associated steatotic liver disease (MASLD). The aim of this study was to determine whether adeno-associated virus serotype 8 (AAV8) mediated hepatocyte-specific overexpression of (AAV8-Fads1) attenuates western diet-induced metabolic phenotypes in a rat model. Male weanling Sprague-Dawley rats were fed with a chow diet, or low-fat high-fructose (LFHFr) or high-fat high-fructose diet (HFHFr) ad libitum for 8 weeks. Metabolic phenotypes were evaluated at the endpoint. AAV8-Fads1 injection restored hepatic FADS1 protein levels in both LFHFr and HFHFr-fed rats. While AAV8-Fads1 injection led to improved glucose tolerance and insulin signaling in LFHFr-fed rats, it significantly reduced plasma triglyceride (by ~50%) and hepatic cholesterol levels (by ~25%) in HFHFr-fed rats. Hepatic lipidomics analysis showed that FADS1 activity was rescued by AAV8-FADS1 in HFHFr-fed rats, as shown by the restored arachidonic acid (AA)/dihomo-γ-linolenic acid (DGLA) ratio, and that was associated with reduced monounsaturated fatty acid (MUFA). Our data suggest that the beneficial role of AAV8-Fads1 is likely mediated by the inhibition of fatty acid re-esterification. FADS1 is a promising therapeutic target for MASLD in a diet-dependent manner.
Topics: Animals; Male; Rats; Delta-5 Fatty Acid Desaturase; Dependovirus; Diet, Western; Disease Models, Animal; Fatty Acid Desaturases; Fructose; Hepatocytes; Liver; Phenotype; Rats, Sprague-Dawley; Triglycerides
PubMed: 38732052
DOI: 10.3390/ijms25094836 -
Virology Journal May 2024The immature and suppressed immune response makes transplanted children a special susceptible group to Parvovirus B19 (PVB19). However, the clinical features of...
BACKGROUND
The immature and suppressed immune response makes transplanted children a special susceptible group to Parvovirus B19 (PVB19). However, the clinical features of transplanted children with PVB19 infection haven't been comprehensively described.
METHODS
We searched the medical records of all the transplant recipients who attended the Children's Hospital of Fudan University from 1 Oct 2020 to 31 May 2023, and reviewed the medical literature for PVB19 infection cases among transplanted children.
RESULTS
A total of 10 cases of PVB19 infection were identified in 201 transplanted children at our hospital, and the medical records of each of these cases were shown. Also, we retrieved 40 cases of PVB19 infection among transplanted children from the literature, thus summarizing a total of 50 unique cases of PVB19 infection. The median time to the first positive PVB19 DNA detection was 14 weeks post-transplantation. PVB19 IgM and IgG were detected in merely 26% and 24% of the children, respectively. The incidence of graft loss/dysfunction was as high as 36%. Hematopoietic stem cell transplant (HSCT) recipients showed higher PVB19 load, lower HGB level, greater platelet damage, lower PVB19 IgM/IgG positive rates, and more graft dysfunction than solid-organ transplant (SOT) recipients, indicating a more incompetent immune system.
CONCLUSIONS
Compared with the published data of transplanted adults, transplanted children displayed distinct clinical features upon PVB19 infection, including lower PVB19 IgM/IgG positive rates, more graft dysfunction, and broader damage on hematopoietic cell lines, which was even more prominent in HSCT recipients, thus should be of greater concern.
Topics: Humans; Parvovirus B19, Human; Child; Female; Male; Child, Preschool; Parvoviridae Infections; Hematopoietic Stem Cell Transplantation; Antibodies, Viral; Infant; Adolescent; Immunoglobulin M; Immunoglobulin G; Transplant Recipients; DNA, Viral; Viral Load; Organ Transplantation
PubMed: 38730285
DOI: 10.1186/s12985-024-02380-4 -
Journal of Parkinson's Disease 2024Parkinson's disease (PD) is characterized by alpha-synuclein (α-Syn) pathology, neurodegeneration and neuroinflammation. Human leukocyte antigen (HLA) variants...
BACKGROUND
Parkinson's disease (PD) is characterized by alpha-synuclein (α-Syn) pathology, neurodegeneration and neuroinflammation. Human leukocyte antigen (HLA) variants associated with PD and α-Syn specific CD4+ T lymphocytes in PD patients highlight the importance of antigen presentation in PD etiology. The class II transactivator (CIITA) regulates major histocompatibility complex class II (MHCII) expression. Reduced Ciita levels significantly increase α-Syn pathology, nigrostriatal neurodegeneration and behavioral deficits in α-Syn-induced rat PD models.
OBJECTIVE
Characterize immune profiles associated with enhanced PD-like pathology observed in rats expressing lower Ciita levels (DA.VRA4) compared to the background strain (DA).
METHODS
To model PD, we combined rAAV-mediated α-Syn overexpression in the substantia nigra with striatal injection of α-Syn preformed fibrils. Immune profiles in brain and blood were analyzed by flow cytometry and multiplexed ELISA in naïve rats, 4- and 8 weeks post rAAV injection.
RESULTS
Flow cytometry showed Ciita-dependent regulation of MHCII on microglia, brain macrophages and circulating myeloid cells. The MHCII-dependent microglial response was highest at 4 weeks post rAAV injection, whereas the MHCII levels in circulating myeloid cells was highest at 8 weeks. There was no major infiltration of macrophages or T lymphocytes into the CNS in response to α-Syn and only subtle Ciita- and/or α-Syn-dependent changes in the T lymphocyte compartment. Lower Ciita levels were consistently associated with higher TNF levels in serum.
CONCLUSIONS
Ciita regulates susceptibility to PD-like pathology through minor but detectable changes in resident and peripheral immune cells and TNF levels, indicating that mild immunomodulatory therapies could have therapeutic effects in PD.
Topics: Animals; alpha-Synuclein; Rats; Disease Models, Animal; Trans-Activators; Parkinson Disease; Nuclear Proteins; Substantia Nigra; Male; Dependovirus; Microglia
PubMed: 38728204
DOI: 10.3233/JPD-240062 -
Behavioural Brain Research Jun 2024Hippocampus is essential for episodic memory formation, lesion studies demonstrating its role especially in processing spatial and temporal information. Further, adult...
Hippocampus is essential for episodic memory formation, lesion studies demonstrating its role especially in processing spatial and temporal information. Further, adult hippocampal neurogenesis (AHN) in the dentate gyrus (DG) has also been linked to learning. To study hippocampal neuronal activity during events like learning, in vivo calcium imaging has become increasingly popular. It relies on the use of adeno-associated viral (AAV) vectors, which seem to lead to a decrease in AHN when applied on the DG. More notably, imaging requires the implantation of a relatively large lens into the tissue. Here, we examined how injection of an AAV vector and implantation of a 1-mm-diameter lens into the dorsal DG routinely used to image calcium activity impact the behavior of adult male C57BL/6 mice. To this aim, we conducted open-field, object-recognition and object-location tasks at baseline, after AAV vector injection, and after lens implantation. Finally, we determined AHN from hippocampal slices using a doublecortin-antibody. According to our results, the operations needed for in vivo imaging of the dorsal DG did not have adverse effects on behavior, although we noticed a decrease in AHN ipsilaterally to the operations. Thus, our results suggest that in vivo imaging can be safely used to, for example, correlate patterns of calcium activity with learned behavior. One should still keep in mind that the defects on the operated side might be functionally compensated by the (hippocampus in the) contralateral hemisphere.
Topics: Animals; Neurogenesis; Male; Mice, Inbred C57BL; Hippocampus; Mice; Calcium; Behavior, Animal; Recognition, Psychology; Dentate Gyrus; Dependovirus; Genetic Vectors; Functional Laterality
PubMed: 38723676
DOI: 10.1016/j.bbr.2024.115042 -
JCI Insight May 2024Clinical trials delivering high doses of adeno-associated viruses (AAVs) expressing truncated dystrophin molecules (microdystrophins) are underway for Duchenne muscular...
Clinical trials delivering high doses of adeno-associated viruses (AAVs) expressing truncated dystrophin molecules (microdystrophins) are underway for Duchenne muscular dystrophy (DMD). We examined the efficiency and efficacy of this strategy with 4 microdystrophin constructs (3 in clinical trials and a variant of the largest clinical construct), in a severe mouse model of DMD, using AAV doses comparable with those in clinical trials. We achieved high levels of microdystrophin expression in striated muscles with cardiac expression approximately 10-fold higher than that observed in skeletal muscle. Significant, albeit incomplete, correction of skeletal muscle disease was observed. Surprisingly, a lethal acceleration of cardiac disease occurred with 2 of the microdystrophins. The detrimental cardiac effect appears to be caused by variable competition (dependent on microdystrophin design and expression level) between microdystrophin and utrophin at the cardiomyocyte membrane. There may also be a contribution from an overloading of protein degradation. The significance of these observations for patients currently being treated with AAV-microdystrophin therapies is unclear since the levels of expression being achieved in the DMD hearts are unknown. However, these findings suggest that microdystrophin treatments need to avoid excessively high levels of expression in the heart and that cardiac function should be carefully monitored in these patients.
Topics: Muscular Dystrophy, Duchenne; Animals; Genetic Therapy; Dystrophin; Mice; Dependovirus; Muscle, Skeletal; Disease Models, Animal; Utrophin; Humans; Genetic Vectors; Male; Mice, Inbred mdx; Myocytes, Cardiac
PubMed: 38713520
DOI: 10.1172/jci.insight.165869 -
BioRxiv : the Preprint Server For... Mar 2024The initial objective of this study was to shed light on the evolution of small DNA tumor viruses by analyzing assemblies of publicly available deep sequencing...
The initial objective of this study was to shed light on the evolution of small DNA tumor viruses by analyzing assemblies of publicly available deep sequencing datasets. The survey generated a searchable database of contig snapshots representing more than 100,000 Sequence Read Archive records. Using modern structure-aware search tools, we iteratively broadened the search to include an increasingly wide range of other virus families. The analysis revealed a surprisingly diverse range of chimeras involving different virus groups. In some instances, genes resembling known DNA-replication modules or known virion protein operons were paired with unrecognizable sequences that structural predictions suggest may represent previously unknown replicases and novel virion architectures. Discrete clades of an emerging group called adintoviruses were discovered in datasets representing humans and other primates. As a proof of concept, we show that the contig database is also useful for discovering RNA viruses and candidate archaeal phages. The ancillary searches revealed additional examples of chimerization between different virus groups. The observations support a gene-centric taxonomic framework that should be useful for future virus-hunting efforts.
PubMed: 38712252
DOI: 10.1101/2024.03.25.586562 -
Nature Communications May 2024Recombinant adeno-associated viruses (rAAVs) have emerged as promising gene therapy vectors due to their proven efficacy and safety in clinical applications. In...
Recombinant adeno-associated viruses (rAAVs) have emerged as promising gene therapy vectors due to their proven efficacy and safety in clinical applications. In non-human primates (NHPs), rAAVs are administered via suprachoroidal injection at a higher dose. However, high doses of rAAVs tend to increase additional safety risks. Here, we present a novel AAV capsid (AAVv128), which exhibits significantly enhanced transduction efficiency for photoreceptors and retinal pigment epithelial (RPE) cells, along with a broader distribution across the layers of retinal tissues in different animal models (mice, rabbits, and NHPs) following intraocular injection. Notably, the suprachoroidal delivery of AAVv128-anti-VEGF vector completely suppresses the Grade IV lesions in a laser-induced choroidal neovascularization (CNV) NHP model for neovascular age-related macular degeneration (nAMD). Furthermore, cryo-EM analysis at 2.1 Å resolution reveals that the critical residues of AAVv128 exhibit a more robust advantage in AAV binding, the nuclear uptake and endosome escaping. Collectively, our findings highlight the potential of AAVv128 as a next generation ocular gene therapy vector, particularly using the suprachoroidal delivery route.
Topics: Animals; Dependovirus; Genetic Vectors; Genetic Therapy; Mice; Retinal Pigment Epithelium; Choroidal Neovascularization; Rabbits; Humans; Gene Transfer Techniques; Macular Degeneration; Disease Models, Animal; Capsid Proteins; Transduction, Genetic; Vascular Endothelial Growth Factor A; Mice, Inbred C57BL; Retina; Male; HEK293 Cells
PubMed: 38710714
DOI: 10.1038/s41467-024-48221-4 -
Cell Reports. Medicine May 2024Mutations in SOD1 cause amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by motor neuron (MN) loss. We previously discovered that...
Mutations in SOD1 cause amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by motor neuron (MN) loss. We previously discovered that macrophage migration inhibitory factor (MIF), whose levels are extremely low in spinal MNs, inhibits mutant SOD1 misfolding and toxicity. In this study, we show that a single peripheral injection of adeno-associated virus (AAV) delivering MIF into adult SOD1 mice significantly improves their motor function, delays disease progression, and extends survival. Moreover, MIF treatment reduces neuroinflammation and misfolded SOD1 accumulation, rescues MNs, and corrects dysregulated pathways as observed by proteomics and transcriptomics. Furthermore, we reveal low MIF levels in human induced pluripotent stem cell-derived MNs from familial ALS patients with different genetic mutations, as well as in post mortem tissues of sporadic ALS patients. Our findings indicate that peripheral MIF administration may provide a potential therapeutic mechanism for modulating misfolded SOD1 in vivo and disease outcome in ALS patients.
Topics: Macrophage Migration-Inhibitory Factors; Amyotrophic Lateral Sclerosis; Animals; Humans; Motor Neurons; Superoxide Dismutase-1; Mice; Induced Pluripotent Stem Cells; Intramolecular Oxidoreductases; Mice, Transgenic; Dependovirus; Disease Models, Animal; Male; Mutation; Female; Protein Folding
PubMed: 38703766
DOI: 10.1016/j.xcrm.2024.101546 -
Bioprocess and Biosystems Engineering Jun 2024Ultracentrifugation is an attractive method for separating full and empty capsids, exploiting their density difference. Changes of the serotype/capsid, density of...
Ultracentrifugation is an attractive method for separating full and empty capsids, exploiting their density difference. Changes of the serotype/capsid, density of loading material, or the genetic information contained in the adeno-associated viruses (AAVs) require the adaptation of the harvesting parameters and the density gradient loaded onto the centrifuge. To streamline these adaptations, a mathematical model could support the design and testing of operating conditions.Here, hybrid models, which combine empirical functions with artificial neural networks, are proposed to describe the separation of full and empty capsids as a function of material and operational parameters, i.e., the harvest model. In addition, critical quality attributes are estimated by a quality model which is operating on top of the harvest model. The performance of these models was evaluated using test data and two additional blind runs. Also, a "what-if" analysis was conducted to investigate whether the models' predictions align with expectations.It is concluded that the models are sufficiently accurate to support the design of operating conditions, though the accuracy and applicability of the models can further be increased by training them on more specific data with higher variability.
Topics: Dependovirus; Ultracentrifugation; Virion; Neural Networks, Computer
PubMed: 38703202
DOI: 10.1007/s00449-024-03014-3