Analysis of genes involved in cell proliferation, adhesion, and control of apoptosis during embryonic neurogenesis in Induced Pluripotent Stem Cells (iPSCs) from patients with Focal Cortical Dysplasia

In vitro human cell culture models in a bench-to-bedside approach to epilepsy

Epilepsy is the most common chronic neurological disease, affecting nearly 1%-2% of the world's population. Current pharmacological treatment and regimen adjustments are aimed at controlling seizures; however, they are ineffective in one-third of the patients. Although neuronal hyperexcitability was previously thought to be mainly due to ion channel alterations, current research has revealed other contributing molecular pathways, including processes involved in cellular signaling, energy metabolism, protein synthesis, axon guidance, inflammation, and others. Some forms of drug-resistant epilepsy are caused by genetic defects that constitute potential targets for precision therapy. Although such approaches are increasingly important, they are still in the early stages of development. This review aims to provide a summary of practical aspects of the employment of in vitro human cell culture models in epilepsy diagnosis, treatment, and research. First, we briefly summarize the genetic testing that may result in the detection of candidate pathogenic variants in genes involved in epilepsy pathogenesis. Consequently, we review existing in vitro cell models, including induced pluripotent stem cells and differentiated neuronal cells, providing their specific properties, validity, and employment in research pipelines. We cover two methodological approaches. The first approach involves the utilization of somatic cells directly obtained from individual patients, while the second approach entails the utilization of characterized cell lines. The models are evaluated in terms of their research and clinical benefits, relevance to the in vivo conditions, legal and ethical aspects, time and cost demands, and available published data. Despite the methodological, temporal, and financial demands of the reviewed models they possess high potential to be used as robust systems in routine testing of pathogenicity of detected variants in the near future and provide a solid experimental background for personalized therapy of genetic epilepsies. PLAIN LANGUAGE SUMMARY: Epilepsy affects millions worldwide, but current treatments fail for many patients. Beyond traditional ion channel alterations, various genetic factors contribute to the disorder's complexity. This review explores how in vitro human cell models, either from patients or from cell lines, can aid in understanding epilepsy's genetic roots and developing personalized therapies. While these models require further investigation, they offer hope for improved diagnosis and treatment of genetic forms of epilepsy.

Epileptogenesis and drug-resistant in focal cortical dysplasias: Update on clinical, cellular, and molecular markers

Focal cortical dysplasia (FCD) is a cortical malformation in brain development and is considered as one of the major causes of drug-resistant epilepsiesin children and adults. The pathogenesis of FCD is yet to be fully understood. Imaging markers such as MRI are currently the surgeons major obstacle due to the difficulty in delimiting the precise dysplasic area and a mosaic brain where there is epileptogenic tissue invisible to MRI. Also increased gene expression and activity may be responsible for the alterations in cell proliferation, migration, growth, and survival. Altered expressions were found, particularly in the PI3K/AKT/mTOR pathway. Surgery is still considered the most effective treatment option, due to drug-resistance, and up to 60 % of patients experience complete seizure control, varying according to the type and location of FCD. Both genetic and epigenetic factors may be involved in the pathogenesis of FCD, and there is no conclusive evidence whether these alterations are inherited or have an environmental origin.

Human In Vitro Models of Epilepsy Using Embryonic and Induced Pluripotent Stem Cells

The challenges in making animal models of complex human epilepsy phenotypes with varied aetiology highlights the need to develop alternative disease models that can address the limitations of animal models by effectively recapitulating human pathophysiology. The advances in stem cell technology provide an opportunity to use human iPSCs to make disease-in-a-dish models. The focus of this review is to report the current information and progress in the generation of epileptic patient-specific iPSCs lines, isogenic control cell lines, and neuronal models. These in vitro models can be used to study the underlying pathological mechanisms of epilepsies, anti-seizure medication resistance, and can also be used for drug testing and drug screening with their isogenic control cell lines.

miR-146a/KLF4 axis in epileptic mice: a novel regulator of synaptic plasticity involving STAT3 signaling

OBJECTIVE

This study is aimed to investigate the mechanism of miR-146a/KLF4 axis regarding epilepsy seizure and synaptic plasticity.

METHODS

Pentylenetetrazol (PTZ)-kindling mouse model of epilepsy was established and evaluated by Racine's scale. PTZ-treated mice were subjected to stereotactic injection of miR-146a antagomir and pre-KLF4 to verify the role of miR-146a and KLF4 in mice. Primary hippocampal neurons from fetal mouse were isolated and identified through immunofluorescence for microtubule-associated protein (MAP)-2. Cellular models of epilepsy were prepared using magnesium-free extracellular fluid and then the neurons were transfected with miR-146a antagomir, miR-146a agomir, miR-146a agomir + pre-KLF4, AG490 (an inhibitor of STAT3 signal pathway) or miR-146a agomir + AG490. The binding site between miR-146a and KLF4 was predicted and identified. The expression levels of miR-146a, KLF4, CREB, Synaptotagmin-11 (SYT11), and STAT3-related proteins were measured in addition to the morphology of neurons and length of neurite. The severity of synaptic plasticity was assessed according to the levels of CREB and SYT11.

RESULTS

The expression of miR-146a was elevated and KLF4 expression was decreased in epileptic mice. Stereotactic injection of miR-146a antagomir and pre-KLF4 reduced the seizure scores of epileptic mice. Transfection of miR-146a antagomir or pre-KLF4 could attenuate synaptic plasticity in epileptic mice and epileptic cellular models. miR-146a can negatively regulate KLF4 in epileptic cellular models to mediate synaptic plasticity. Epilepsy was attenuated in AG490 and miR-146a agomir + AG490 groups compared with that in Model group.

CONCLUSION

miR-146a inhibits KLF4 to activate STAT3, thus promoting synaptic plasticity in epileptic mice.

New Application of Osteogenic Differentiation from HiPS Stem Cells for Evaluating the Osteogenic Potential of Nanomaterials in Dentistry

Objective: HiPS stem cells are commonly used for the study of medical disorders. The laboratory in which this study was conducted uses these cells for examining the treatment and cure of neurodegenerative diseases. Bone regeneration poses the greatest challenge for an oral surgeon both in terms of increased implant osseointegration and reducing bone healing times. The aim of this study was to validate the protocol in the literature to produce and then test in vitro osteoblasts with different nanomaterials to simulate bone regeneration. Method: hiPS clones (#2, #4, and #8) were differentiated into an osteoblast cell culture tested for alizarin red staining and for alkaline phosphatase testing at 14, 21 and 28 days, after the cells were plated. Results: The cells showed diffuse positivity under alizarin red staining and the alkaline phosphatase (ALP)-test, showing small formations of calcium clusters. Conclusion: Despite the limitations of our study, it is a starting point for further protocols, laying a solid foundation for research in the field of bone regeneration through the use of stem cells.

Self and the Brain. The Immune Metaphor

One of the fundamental questions in neuroscience is how brain activity relates to conscious experience. Even though self-consciousness is considered an emergent property of the brain network, a quantum physics-based theory assigns a momentum of consciousness to the single neuron level. In this work, we present a brain self theory from an evolutionary biological perspective by analogy with the immune self. In this scheme, perinatal reactivity to self inputs would guide the selection of neocortical neurons within the subplate, similarly to T lymphocytes in the thymus. Such self-driven neuronal selection would enable effective discrimination of external inputs and avoid harmful "autoreactive" responses. Multiple experimental and clinical evidences for this model are provided. Based on this self tenet, we outline the postulates of the so-called autophrenic diseases, to then make the case for schizophrenia, an archetypic disease with rupture of the self. Implications of this model are discussed, along with potential experimental verification.