scholarly journals MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons

2019 ◽  
Vol 133 (4) ◽  
pp. 583-595 ◽  
Author(s):  
Fumiko Nakazeki ◽  
Itaru Tsuge ◽  
Takahiro Horie ◽  
Keiko Imamura ◽  
Kayoko Tsukita ◽  
...  
Keyword(s):  
Therapeutic Target ◽  
Cortical Neurons ◽  
Hereditary Spastic Paraplegia ◽  
Regulatory Element ◽  
Induced Pluripotent Stem Cell ◽  
Cholesterol Homeostasis ◽  
Locked Nucleic Acid ◽  
Spastic Paraplegia ◽  
Potential Therapeutic Target ◽  
Human Neurons

Abstract Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3′-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4.

scholarly journals Stop-gain mutations in UBAP1 cause pure autosomal-dominant spastic paraplegia

Brain ◽  
2019 ◽  
Vol 142 (8) ◽  
pp. 2238-2252 ◽  
Author(s):  
Xiang Lin ◽  
Hui-Zhen Su ◽  
En-Lin Dong ◽  
Xiao-Hong Lin ◽  
Miao Zhao ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Cortical Neurons ◽  
Hereditary Spastic Paraplegia ◽  
Autosomal Dominant ◽  
Wild Type Mouse ◽  
Spastic Paraplegia ◽  
Endosomal Sorting ◽  
Hereditary Spastic Paraplegias ◽  
Cultured Cortical Neurons

Abstract Hereditary spastic paraplegias refer to a heterogeneous group of neurodegenerative disorders resulting from degeneration of the corticospinal tract. Clinical characterization of patients with hereditary spastic paraplegias represents progressive spasticity, exaggerated reflexes and muscular weakness. Here, to expand on the increasingly broad pools of previously unknown hereditary spastic paraplegia causative genes and subtypes, we performed whole exome sequencing for six affected and two unaffected individuals from two unrelated Chinese families with an autosomal dominant hereditary spastic paraplegia and lacking mutations in known hereditary spastic paraplegia implicated genes. The exome sequencing revealed two stop-gain mutations, c.247_248insGTGAATTC (p.I83Sfs*11) and c.526G>T (p.E176*), in the ubiquitin-associated protein 1 (UBAP1) gene, which co-segregated with the spastic paraplegia. We also identified two UBAP1 frameshift mutations, c.324_325delCA (p.H108Qfs*10) and c.425_426delAG (p.K143Sfs*15), in two unrelated families from an additional 38 Chinese pedigrees with autosomal dominant hereditary spastic paraplegias and lacking mutations in known causative genes. The primary disease presentation was a pure lower limb predominant spastic paraplegia. In vivo downregulation of Ubap1 in zebrafish causes abnormal organismal morphology, inhibited motor neuron outgrowth, decreased mobility, and shorter lifespan. UBAP1 is incorporated into endosomal sorting complexes required for transport complex I and binds ubiquitin to function in endosome sorting. Patient-derived truncated form(s) of UBAP1 cause aberrant endosome clustering, pronounced endosome enlargement, and cytoplasmic accumulation of ubiquitinated proteins in HeLa cells and wild-type mouse cortical neuron cultures. Biochemical and immunocytochemical experiments in cultured cortical neurons derived from transgenic Ubap1flox mice confirmed that disruption of UBAP1 leads to dysregulation of both early endosome processing and ubiquitinated protein sorting. Strikingly, deletion of Ubap1 promotes neurodegeneration, potentially mediated by apoptosis. Our study provides genetic and biochemical evidence that mutations in UBAP1 can cause pure autosomal dominant spastic paraplegia.

scholarly journals Sodium channel Nav1.2-L1342P variant displaying complex biophysical properties renders hyperexcitability of cortical neurons derived from human iPSCs

2021 ◽  
Author(s):  
Zhefu Que ◽  
Maria I. Olivero-Acosta ◽  
Jingliang Zhang ◽  
Muriel Eaton ◽  
William C. Skarnes ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Cortical Neurons ◽  
Sodium Current ◽  
Electrode Array ◽  
Induced Pluripotent Stem Cell ◽  
Epileptic Seizures ◽  
Action Potential Firing ◽  
Human Neurons ◽  
Human Ipscs

AbstractWith the wide adoption of whole-exome sequencing in children having seizures, an increasing number of SCN2A variants has been revealed as possible genetic causes of epilepsy. Voltage-gated sodium channel Nav1.2, encoded by gene SCN2A, is strongly expressed in the pyramidal excitatory neurons and supports action potential firing. One recurrent SCN2A variant is L1342P, which was identified in multiple patients with early-onset encephalopathy and intractable seizures. Our biophysical analysis and computational modeling predicted gain-of-function features of this epilepsy-associated Nav1.2 variant. However, the mechanism underlying L1342P mediated seizures and the pharmacogenetics of this variant in human neurons remain unknown. To understand the core phenotypes of the L1342P variant in human neurons, we took advantage of a reference human induced pluripotent stem cell (hiPSC) line, in which L1342P was engineered by CRISPR/Cas9 mediated genome-editing. Using patch-clamping and micro-electrode array (MEA) recording, we found that the cortical neurons derived from hiPSCs carrying heterozygous L1342P variant presented significantly increased intrinsic excitability, higher sodium current density, and enhanced bursting and synchronous network firing, showing clear hyperexcitability phenotypes. Interestingly, the L1342P neuronal culture displayed a degree of resistance to the anti-seizure medication (phenytoin), which likely recapitulated aspects of clinical observation of patients carrying the L1342P variant. In contrast, phrixotoxin-3 (PTx3), a Nav1.2 isoform-specific blocker, was able to potently alleviate spontaneous and chemical-induced hyperexcitability of neurons carrying the L1342P variant. Our results reveal a possible pathogenic underpinning of Nav1.2-L1342P mediated epileptic seizures, and demonstrate the utility of genome-edited hiPSCs as an in vitro platform to advance personalized phenotyping and drug discovery.

scholarly journals In vivo modeling of human neuron dynamics and Down syndrome

Science ◽  
2018 ◽  
Vol 362 (6416) ◽  
pp. eaau1810 ◽  
Author(s):  
Raquel Real ◽  
Manuel Peter ◽  
Antonio Trabalza ◽  
Shabana Khan ◽  
Mark A. Smith ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Cortical Neurons ◽  
Synapse Formation ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Human Stem Cells ◽  
Population Activity ◽  
Human Neurons ◽  
Longitudinal Imaging

Harnessing the potential of human stem cells for modeling the physiology and diseases of cortical circuitry requires monitoring cellular dynamics in vivo. We show that human induced pluripotent stem cell (iPSC)–derived cortical neurons transplanted into the adult mouse cortex consistently organized into large (up to ~100 mm3) vascularized neuron-glia territories with complex cytoarchitecture. Longitudinal imaging of >4000 grafted developing human neurons revealed that neuronal arbors refined via branch-specific retraction; human synaptic networks substantially restructured over 4 months, with balanced rates of synapse formation and elimination; and oscillatory population activity mirrored the patterns of fetal neural networks. Lastly, we found increased synaptic stability and reduced oscillations in transplants from two individuals with Down syndrome, demonstrating the potential of in vivo imaging in human tissue grafts for patient-specific modeling of cortical development, physiology, and pathogenesis.

Sign in / Sign up

Export Citation Format

Share Document