Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Loss of sarcolemmal nNOS is common in acquired and inherited neuromuscular disorders.

ABSTRACT:

Objective

Neuronal nitric oxide synthase (nNOS), normally expressed at the sarcolemmal membrane, is known to be mislocalized to the sarcoplasm in several forms of muscular dystrophy. Our objectives were to characterize further the range of patients manifesting aberrant nNOS sarcolemmal immunolocalization and to study nNOS localization in animal models of nondystrophic myopathy.

Methods

We carried out a retrospective cross-sectional study. We performed immunofluorescent staining for nNOS on biopsy specimens from 161 patients with acquired and nondystrophin inherited neuromuscular conditions. The localization of sarcolemmal nNOS correlated with mobility and functional status. Muscle specimens from mouse models of steroid-induced and starvation-related atrophy were studied for qualitative and quantitative nNOS expression.

Results

Sarcolemmal nNOS staining was abnormal in 42% of patients with inherited myopathic conditions, 25% with acquired myopathic conditions, 57% with neurogenic conditions, and 93% with hypotonia. Interestingly, we found significant associations between mobility status or muscle function and sarcolemmal nNOS expression. Furthermore, mouse models of catabolic stress also demonstrated mislocalization of sarcolemmal nNOS.

Conclusion

Our analyses indicate that nNOS mislocalization is observed in a broad range of nondystrophic neuromuscular conditions associated with impaired mobility status and catabolic stress. Our findings suggest that the assessment of sarcolemmal localization of nNOS represents an important tool for the evaluation of muscle biopsies of patients with a variety of inherited and acquired forms of neuromuscular disorders.

SUBMITTER: Finanger Hedderick EL

PROVIDER: S-EPMC3059139 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Inherited Neuromuscular Disorders: Which Role for Serum Biomarkers?

Project description:Inherited neuromuscular disorders (INMD) are a heterogeneous group of rare diseases that involve muscles, motor neurons, peripheral nerves or the neuromuscular junction. Several different lab abnormalities have been linked to INMD: sometimes they are typical of the disorder, but they usually appear to be less specific. Sometimes serum biomarkers can point out abnormalities in presymtomatic or otherwise asymptomatic patients (e.g., carriers). More often a biomarker of INMD is evaluated by multiple clinicians other than expert in NMD before the diagnosis, because of the multisystemic involvement in INMD. The authors performed a literature search on biomarkers in inherited neuromuscular disorders to provide a practical approach to the diagnosis and the correct management of INMD. A considerable number of biomarkers have been reported that support the diagnosis of INMD, but the role of an expert clinician is crucial. Hence, the complete knowledge of such abnormalities can accelerate the diagnostic workup supporting the referral to specialists in neuromuscular disorders.

| S-EPMC8004068 | biostudies-literature

Dystrophin R16/17-syntrophin PDZ fusion protein restores sarcolemmal nNOS?.

Project description:BackgroundLoss of sarcolemmal nNOS? is a common manifestation in a wide variety of muscle diseases and contributes to the dysregulation of multiple muscle activities. Given the critical role sarcolemmal nNOS? plays in muscle, restoration of sarcolemmal nNOS? should be considered as an important therapeutic goal.MethodsnNOS? is anchored to the sarcolemma by dystrophin spectrin-like repeats 16 and 17 (R16/17) and the syntrophin PDZ domain (Syn PDZ). To develop a strategy that can independently restore sarcolemmal nNOS?, we engineered an R16/17-Syn PDZ fusion construct and tested whether this construct alone is sufficient to anchor nNOS? to the sarcolemma in three different mouse models of Duchenne muscular dystrophy (DMD).ResultsMembrane-associated nNOS? is completely lost in DMD. Adeno-associated virus (AAV)-mediated delivery of the R16/17-Syn PDZ fusion construct successfully restored sarcolemmal nNOS? in all three models. Further, nNOS restoration was independent of the dystrophin-associated protein complex.ConclusionsOur results suggest that the R16/17-Syn PDZ fusion construct is sufficient to restore sarcolemmal nNOS? in the dystrophin-null muscle.

| S-EPMC6251231 | biostudies-literature

Sarcolemmal targeting of nNOS? improves contractile function of mdx muscle.

Project description:Nitric oxide (NO) is a key regulator of skeletal muscle function and metabolism, including vasoregulation, mitochondrial function, glucose uptake, fatigue and excitation-contraction coupling. The main generator of NO in skeletal muscle is the muscle-specific form of neuronal nitric oxide synthase (nNOS?) produced by the NOS1 gene. Skeletal muscle nNOS? is predominantly localized at the sarcolemma by interaction with the dystrophin protein complex (DPC). In Duchenne muscular dystrophy (DMD), loss of dystrophin leads to the mislocalization of nNOS? from the sarcolemma to the cytosol. This perturbation has been shown to impair contractile function and cause muscle fatigue in dystrophic (mdx) mice. Here, we investigated the effect of restoring sarcolemmal nNOS? on muscle contractile function in mdx mice. To achieve this, we designed a modified form of nNOS? (NOS-M) that is targeted to the sarcolemma by palmitoylation, even in the absence of the DPC. When expressed specifically in mdx skeletal muscle, NOS-M significantly attenuates force loss owing to damaging eccentric contractions and repetitive isometric contractions (fatigue), while also improving force recovery after fatigue. Expression of unmodified nNOS? at similar levels does not lead to sarcolemmal association and fails to improve muscle function. Aside from the benefits of sarcolemmal-localized NO production, NOS-M also increased the surface membrane levels of utrophin and other DPC proteins, including ?-dystroglycan, ?-syntrophin and ?-dystrobrevin in mdx muscle. These results suggest that the expression of NOS-M in skeletal muscle may be therapeutically beneficial in DMD and other muscle diseases characterized by the loss of nNOS? from the sarcolemma.

| S-EPMC4690500 | biostudies-other

Inherited and acquired disorders of myelin: The underlying myelin pathology.

Project description:Remyelination is a major therapeutic goal in human myelin disorders, serving to restore function to demyelinated axons and providing neuroprotection. The target disorders that might be amenable to the promotion of this repair process are diverse and increasing in number. They range primarily from those of genetic, inflammatory to toxic origin. In order to apply remyelinating strategies to these disorders, it is essential to know whether the myelin damage results from a primary attack on myelin or the oligodendrocyte or both, and whether indeed these lead to myelin breakdown and demyelination. In some disorders, myelin sheath abnormalities are prominent but demyelination does not occur. This review explores the range of human and animal disorders where myelin pathology exists and focusses on defining the myelin changes in each and their cause, to help define whether they are targets for myelin repair therapy.

| S-EPMC5010953 | biostudies-literature

Cell transplantation strategies for acquired and inherited disorders of peripheral myelin

Project description:Objective: To investigate transplantation of rat Schwann cells or human iPSC-derived neural crest cells and derivatives into models of acquired and inherited peripheral myelin damage. Methods: Primary cultured rat Schwann cells labeled with a fluorescent protein for monitoring at various times after transplantation. Human induced pluripotent stem cells (iPSCs) were differentiated into neural crest stem cells (NCSC), and subsequently toward a Schwann cell lineage via two different protocols. Protocol 1 = treated with MesenPRO with Heregulin. Protocol 2 = coculture with iPSC-derived Motor Neurons. Cell types were characterized using flow cytometry, immunocytochemistry and transcriptomics. Rat Schwann cells and human iPSC-derivatives were transplanted into (i) nude rats pretreated with lysolecithin to induce demyelination or (ii) a transgenic rat model of dysmyelination due to PMP22 overexpression. Results: Rat Schwann cells transplanted into sciatic nerves with either toxic demyelination or genetic dysmyelination engrafted successfully, and migrated longitudinally for relatively long distances, with more limited axial migration. Transplanted Schwann cells engaged existing axons and displaced dysfunctional Schwann cells to form normal appearing myelin. Human iPSC-derived neural crest stem cells and their derivatives shared similar engraftment and migration characteristics to rat Schwann cells after transplantation, but did not further differentiate into Schwann cells or form myelin. Interpretation: These results indicate that cultured Schwann cells surgically delivered to peripheral nerve can engraft and form myelin in either acquired or inherited myelin injury, as proof of concept for pursuing cell therapy for diseases of peripheral nerve. However, lack of reliable technology for generating human iPSC-derived Schwann cells for transplantation therapy remains a barrier in the field.

2018-01-26 | GSE109686 | GEO

Relative incidence of inherited white matter disorders in childhood to acquired pediatric demyelinating disorders.

Project description:Epidemiologic frequencies of pediatric white matter disorders as a class have not been well defined. This is particularly true of genetic disorders of the white matter of the brain. In this study, ICD-9 codes were used to estimate relative incidence rates and descriptive statistics of leukodystrophies, other genetic leukoencephalopathies and acquired demyelinating disease among children residing in the Washington, D.C. metropolitan area. Children being treated at US children's hospitals between January 1, 2004, and December 31, 2009, for acquired demyelinating disease or genetic white matter disorders were captured using the Pediatric Health Information System and the Physician Practice Management system and validated with local electronic medical records. Comparisons were made between genetic white matter disorders and acquired demyelinating disorders, to determine differences in incidence, age, gender, ethnicity, and mortality. Genetic causes of white matter disease identified with ICD-9 codes had an estimated incidence of 1.2/100,000 children in the Washington, DC area. What was of interest was nearly 5 out of 10 cases of pediatric white matter disease of any etiology were attributable to genetic causes. When only progressive white matter diseases were considered, 7 out of 10 cases were attributable to genetic causes, and only 3 out of 10 to progressive acquired demyelinating disease such as multiple sclerosis. These findings signify the important contribution of heritable white matter disorders to pediatric neurologic disease in the Washington, DC, metro area as well as throughout the United States. Continued research of these understudied disorders should compare disease incidence and determinants to validate these findings in different populations.

| S-EPMC3797524 | biostudies-literature

Cell transplantation strategies for acquired and inherited disorders of peripheral myelin.

Project description:Objective:To investigate transplantation of rat Schwann cells or human iPSC-derived neural crest cells and derivatives into models of acquired and inherited peripheral myelin damage. Methods:Primary cultured rat Schwann cells labeled with a fluorescent protein for monitoring at various times after transplantation. Human-induced pluripotent stem cells (iPSCs) were differentiated into neural crest stem cells, and subsequently toward a Schwann cell lineage via two different protocols. Cell types were characterized using flow cytometry, immunocytochemistry, and transcriptomics. Rat Schwann cells and human iPSC derivatives were transplanted into (1) nude rats pretreated with lysolecithin to induce demyelination or (2) a transgenic rat model of dysmyelination due to PMP22 overexpression. Results:Rat Schwann cells transplanted into sciatic nerves with either toxic demyelination or genetic dysmyelination engrafted successfully, and migrated longitudinally for relatively long distances, with more limited axial migration. Transplanted Schwann cells engaged existing axons and displaced dysfunctional Schwann cells to form normal-appearing myelin. Human iPSC-derived neural crest stem cells and their derivatives shared similar engraftment and migration characteristics to rat Schwann cells after transplantation, but did not further differentiate into Schwann cells or form myelin. Interpretation:These results indicate that cultured Schwann cells surgically delivered to peripheral nerve can engraft and form myelin in either acquired or inherited myelin injury, as proof of concept for pursuing cell therapy for diseases of peripheral nerve. However, lack of reliable technology for generating human iPSC-derived Schwann cells for transplantation therapy remains a barrier in the field.

| S-EPMC5817839 | biostudies-literature

RNA Targeting in Inherited Neuromuscular Disorders: Novel Therapeutic Strategies to Counteract Mis-Splicing.

Project description:Neuromuscular disorders represent multifaceted abnormal conditions, with little or no cure, leading to patient deaths from complete muscle wasting and atrophy. Despite strong efforts in the past decades, development of effective treatments is still urgently needed. Advent of next-generation sequencing technologies has allowed identification of novel genes and mutations associated with neuromuscular pathologies, highlighting splicing defects as essential players. Deciphering the significance and relative contributions of defective RNA metabolism will be instrumental to address and counteract these malignancies. We review here recent progress on the role played by alternative splicing in ensuring functional neuromuscular junctions (NMJs), and its involvement in the pathogenesis of NMJ-related neuromuscular disorders, with particular emphasis on congenital myasthenic syndromes and muscular dystrophies. We will also discuss novel strategies based on oligonucleotides designed to bind their cognate sequences in the RNA or targeting intermediary of mRNA metabolism. These efforts resulted in several chemical classes of RNA molecules that have recently proven to be clinically effective, more potent and better tolerated than previous strategies.

| S-EPMC8616048 | biostudies-literature

Protein Destabilization as a Common Factor in Diverse Inherited Disorders.

Project description:Protein destabilization by amino acid substitutions is proposed to play a prominent role in widespread inherited human disorders, not just those known to involve protein misfolding and aggregation. To test this hypothesis, we computationally evaluate the effects on protein stability of all possible amino acid substitutions in 20 disease-associated proteins with multiple identified pathogenic missense mutations. For 18 of the 20 proteins studied, substitutions at known positions of pathogenic mutations are significantly more likely to destabilize the native protein fold (as indicated by more positive values of ??G). Thus, positions identified as sites of disease-associated mutations, as opposed to non-disease-associated sites, are predicted to be more vulnerable to protein destabilization upon amino acid substitution. This finding supports the notion that destabilization of native protein structure underlies the pathogenicity of broad set of missense mutations, even in cases where reduced protein stability and/or aggregation are not characteristic of the disease state.

| S-EPMC4712097 | biostudies-literature

Dystrophin R16/17 protein therapy restores sarcolemmal nNOS in trans and improves muscle perfusion and function.

Project description:BACKGROUND:Delocalization of neuronal nitric oxide synthase (nNOS) from the sarcolemma leads to functional muscle ischemia. This contributes to the pathogenesis in cachexia, aging and muscular dystrophy. Mutations in the gene encoding dystrophin result in Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). In many BMD patients and DMD patients that have been converted to BMD by gene therapy, sarcolemmal nNOS is missing due to the lack of dystrophin nNOS-binding domain. METHODS:Dystrophin spectrin-like repeats 16 and 17 (R16/17) is the sarcolemmal nNOS localization domain. Here we explored whether R16/17 protein therapy can restore nNOS to the sarcolemma and prevent functional ischemia in transgenic mice which expressed an R16/17-deleted human micro-dystrophin gene in the dystrophic muscle. The palmitoylated R16/17.GFP fusion protein was conjugated to various cell-penetrating peptides and produced in the baculovirus-insect cell system. The best fusion protein was delivered to the transgenic mice and functional muscle ischemia was quantified. RESULTS:Among five candidate cell-penetrating peptides, the mutant HIV trans-acting activator of transcription (TAT) protein transduction domain (mTAT) was the best in transferring the R16/17.GFP protein to the muscle. Systemic delivery of the mTAT.R16/17.GFP protein to micro-dystrophin transgenic mice successfully restored sarcolemmal nNOS without inducing T cell infiltration. More importantly, R16/17 protein therapy effectively prevented treadmill challenge-induced force loss and improved muscle perfusion during contraction. CONCLUSIONS:Our results suggest that R16/17 protein delivery is a highly promising therapy for muscle diseases involving sarcolemmal nNOS delocalizaton.

| S-EPMC6607532 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data